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4.4.38+fslc #4
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commit bd768e1 upstream. vcpu->arch.wbinvd_dirty_mask may still be used after freeing it, corrupting memory. For example, the following call trace may set a bit in an already freed cpu mask: kvm_arch_vcpu_load vcpu_load vmx_free_vcpu_nested vmx_free_vcpu kvm_arch_vcpu_free Fix this by deferring freeing of wbinvd_dirty_mask. Signed-off-by: Ido Yariv <ido@wizery.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ede5f3e upstream. The ERET instruction to return from exception is used for returning from exception level (Status.EXL) and error level (Status.ERL). If both bits are set however we should be returning from ERL first, as ERL can interrupt EXL, for example when an NMI is taken. KVM however checks EXL first. Fix the order of the checks to match the pseudocode in the instruction set manual. Fixes: e685c68 ("KVM/MIPS32: Privileged instruction/target branch emulation.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 641089c upstream. Make sure the copied up file hits the disk before renaming to the final destination. If this is not done then the copy-up may corrupt the data in the file in case of a crash. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…call entry commit 6ed5183 upstream. We have one critical section in the syscall entry path in which we switch from the userspace stack to kernel stack. In the event of an external interrupt, the interrupt code distinguishes between those two states by analyzing the value of sr7. If sr7 is zero, it uses the kernel stack. Therefore it's important, that the value of sr7 is in sync with the currently enabled stack. This patch now disables interrupts while executing the critical section. This prevents the interrupt handler to possibly see an inconsistent state which in the worst case can lead to crashes. Interestingly, in the syscall exit path interrupts were already disabled in the critical section which switches back to the userspace stack. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0ea1e4a upstream. According to the spec, if the VIRTIO_RING_F_EVENT_IDX feature bit is negotiated the driver MUST set flags to 0. Not dirtying the available ring in virtqueue_disable_cb also has a minor positive performance impact, improving L1 dcache load missed by ~0.5% in vring_bench. Writes to the used event field (vring_used_event) are still unconditional. Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3456376 upstream. Commit c6017e7 ("virtio: console: add locks around buffer removal in port unplug path") added locking around the freeing of buffers in the vq. However, when free_buf() is called with can_sleep = true and rproc is enabled, it calls dma_free_coherent() directly, requiring interrupts to be enabled. Currently a WARNING is triggered due to the spin locking around free_buf, with a call stack like this: WARNING: CPU: 3 PID: 121 at ./include/linux/dma-mapping.h:433 free_buf+0x1a8/0x288 Call Trace: [<8040c538>] show_stack+0x74/0xc0 [<80757240>] dump_stack+0xd0/0x110 [<80430d98>] __warn+0xfc/0x130 [<80430ee0>] warn_slowpath_null+0x2c/0x3c [<807e7c6c>] free_buf+0x1a8/0x288 [<807ea590>] remove_port_data+0x50/0xac [<807ea6a0>] unplug_port+0xb4/0x1bc [<807ea858>] virtcons_remove+0xb0/0xfc [<807b6734>] virtio_dev_remove+0x58/0xc0 [<807f918c>] __device_release_driver+0xac/0x134 [<807f924c>] device_release_driver+0x38/0x50 [<807f7edc>] bus_remove_device+0xfc/0x130 [<807f4b74>] device_del+0x17c/0x21c [<807f4c38>] device_unregister+0x24/0x38 [<807b6b50>] unregister_virtio_device+0x28/0x44 Fix this by restructuring the loops to allow the locks to only be taken where it is necessary to protect the vqs, and release it while the buffer is being freed. Fixes: c6017e7 ("virtio: console: add locks around buffer removal in port unplug path") Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dcb2ff5 upstream. If a default leg has failed, any read will cause a new operational default leg to be selected and the read is resubmitted. But until now the read will return failure even though it was successful due to resubmission. The reason for this is bio->bi_error was not being cleared before resubmitting the bio. Fix by clearing bio->bi_error before resubmission. Fixes: 4246a0b ("block: add a bi_error field to struct bio") Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit da25311 upstream. The Schenker XMG C504 is a rebranded Gigabyte P35 v2 laptop. Therefore it also needs a keyboard reset to detect the Elantech touchpad. Otherwise the touchpad appears to be dead. With this patch the touchpad is detected: $ dmesg | grep -E "(i8042|Elantech|elantech)" [ 2.675399] i8042: PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x60,0x64 irq 1,12 [ 2.680372] i8042: Attempting to reset device connected to KBD port [ 2.789037] serio: i8042 KBD port at 0x60,0x64 irq 1 [ 2.791586] serio: i8042 AUX port at 0x60,0x64 irq 12 [ 2.813840] input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input4 [ 3.811431] psmouse serio1: elantech: assuming hardware version 4 (with firmware version 0x361f0e) [ 3.825424] psmouse serio1: elantech: Synaptics capabilities query result 0x00, 0x15, 0x0f. [ 3.839424] psmouse serio1: elantech: Elan sample query result 03, 58, 74 [ 3.911349] input: ETPS/2 Elantech Touchpad as /devices/platform/i8042/serio1/input/input6 Signed-off-by: Patrick Scheuring <patrick.scheuring.dev@gmail.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 667121a upstream. The IP-over-1394 driver firewire-net lacked input validation when handling incoming fragmented datagrams. A maliciously formed fragment with a respectively large datagram_offset would cause a memcpy past the datagram buffer. So, drop any packets carrying a fragment with offset + length larger than datagram_size. In addition, ensure that - GASP header, unfragmented encapsulation header, or fragment encapsulation header actually exists before we access it, - the encapsulated datagram or fragment is of nonzero size. Reported-by: Eyal Itkin <eyal.itkin@gmail.com> Reviewed-by: Eyal Itkin <eyal.itkin@gmail.com> Fixes: CVE 2016-8633 Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e9300a4 upstream. RFC 2734 defines the datagram_size field in fragment encapsulation headers thus: datagram_size: The encoded size of the entire IP datagram. The value of datagram_size [...] SHALL be one less than the value of Total Length in the datagram's IP header (see STD 5, RFC 791). Accordingly, the eth1394 driver of Linux 2.6.36 and older set and got this field with a -/+1 offset: ether1394_tx() /* transmit */ ether1394_encapsulate_prep() hdr->ff.dg_size = dg_size - 1; ether1394_data_handler() /* receive */ if (hdr->common.lf == ETH1394_HDR_LF_FF) dg_size = hdr->ff.dg_size + 1; else dg_size = hdr->sf.dg_size + 1; Likewise, I observe OS X 10.4 and Windows XP Pro SP3 to transmit 1500 byte sized datagrams in fragments with datagram_size=1499 if link fragmentation is required. Only firewire-net sets and gets datagram_size without this offset. The result is lacking interoperability of firewire-net with OS X, Windows XP, and presumably Linux' eth1394. (I did not test with the latter.) For example, FTP data transfers to a Linux firewire-net box with max_rec smaller than the 1500 bytes MTU - from OS X fail entirely, - from Win XP start out with a bunch of fragmented datagrams which time out, then continue with unfragmented datagrams because Win XP temporarily reduces the MTU to 576 bytes. So let's fix firewire-net's datagram_size accessors. Note that firewire-net thereby loses interoperability with unpatched firewire-net, but only if link fragmentation is employed. (This happens with large broadcast datagrams, and with large datagrams on several FireWire CardBus cards with smaller max_rec than equivalent PCI cards, and it can be worked around by setting a small enough MTU.) Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ea72093 upstream. In mac80211, multicast A-MSDUs are accepted in many cases that they shouldn't be accepted in: * drop A-MSDUs with a multicast A1 (RA), as required by the spec in 9.11 (802.11-2012 version) * drop A-MSDUs with a 4-addr header, since the fourth address can't actually be useful for them; unless 4-address frame format is actually requested, even though the fourth address is still not useful in this case, but ignored Accepting the first case, in particular, is very problematic since it allows anyone else with possession of a GTK to send unicast frames encapsulated in a multicast A-MSDU, even when the AP has client isolation enabled. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
… devices commit 1e793f6 upstream. Commit 02b01e0 ("megaraid_sas: return sync cache call with success") modified the driver to successfully complete SYNCHRONIZE_CACHE commands without passing them to the controller. Disk drive caches are only explicitly managed by controller firmware when operating in RAID mode. So this commit effectively disabled writeback cache flushing for any drives used in JBOD mode, leading to data integrity failures. [mkp: clarified patch description] Fixes: 02b01e0 Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4d2b496 upstream. map_storep was not being vfree()'d in the module_exit call. Signed-off-by: Ewan D. Milne <emilne@redhat.com> Reviewed-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2bf7dc8 upstream. The arcmsr driver failed to pass SYNCHRONIZE CACHE to controller firmware. Depending on how drive caches are handled internally by controller firmware this could potentially lead to data integrity problems. Ensure that cache flushes are passed to the controller. [mkp: applied by hand and removed unused vars] Signed-off-by: Ching Huang <ching2048@areca.com.tw> Reported-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 45c7a49 upstream. platform_get_resource can be returned the NULL pointer. Then regs->start should be referred to NULL Pointer. devm_ioremap_resource() checks whether res is NULL or not. Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9dc7996 upstream. This reverts commit 1a73834. It caused at least some Kaveri laptops to incorrectly report DisplayPort connectors as connected. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97857 Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb9a5b0 upstream. Limit clocks on a specific HD86xx part to avoid crashes (while awaiting an appropriate PP fix). Signed-off-by: Tom St Denis <tom.stdenis@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7dc86ef upstream. Consolidate existing quirks. Fixes stability issues on some kickers. Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 537b4b4 upstream. The read is taking a considerable amount of time (about 50us on this machine). The register does not ever hold anything other than the ring ID that is updated in this exact function, so there is no need for the read modify write cycle. This chops off a big chunk of the time spent in hardirq disabled context, as this function is called multiple times in the interrupt handler. With this change applied radeon won't show up in the list of the worst IRQ latency offenders anymore, where it was a regular before. Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Lucas Stach <dev@lynxeye.de> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4da5caa upstream. Only certain types of pdts have the DDC bus registered, so check for that before we attempt the EDID read. Othwewise we risk playing around with an i2c adapter that doesn't actually exist. Cc: Carlos Santa <carlos.santa@intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Tested-by: Carlos Santa <carlos.santa@intel.com> Tested-by: Kirill A. Shutemov <kirill@shutemov.name> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97666 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1477472755-15288-5-git-send-email-ville.syrjala@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67befc6 upstream. Ingo reported following build failure: $ make clean install ... CC plugin_kmem.o fixdep: error opening depfile: ./.plugin_hrtimer.o.d: No such file or directory /home/mingo/tip/tools/build/Makefile.build:77: recipe for target 'plugin_hrtimer.o' failed make[3]: *** [plugin_hrtimer.o] Error 2 Makefile:189: recipe for target 'plugin_hrtimer-in.o' failed make[2]: *** [plugin_hrtimer-in.o] Error 2 Makefile.perf:414: recipe for target 'libtraceevent_plugins' failed make[1]: *** [libtraceevent_plugins] Error 2 make[1]: *** Waiting for unfinished jobs.... Currently we have the install-traceevent-plugins target being dependent on $(LIBTRACEEVENT), which will actualy not build any plugin. So the install-traceevent-plugins target itself will try to build plugins, but.. Plugins built is also triggered by perf build itself via libtraceevent_plugins target. This might cause a race having one make thread removing temp files from another and result in above error. Fixing this by having proper plugins build dependency before installing plugins. Reported-and-Tested-by:: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1448546044-28973-3-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Thomas Backlund <tmb@mageia.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1cf3874 upstream. xen_cleanhighmap() is operating on level2_kernel_pgt only. The upper bound of the loop setting non-kernel-image entries to zero should not exceed the size of level2_kernel_pgt. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1e407ee upstream. gcc-6 correctly warns about a out of bounds access arch/powerpc/kernel/ptrace.c:407:24: warning: index 32 denotes an offset greater than size of 'u64[32][1] {aka long long unsigned int[32][1]}' [-Warray-bounds] offsetof(struct thread_fp_state, fpr[32][0])); ^ check the end of array instead of beginning of next element to fix this Signed-off-by: Khem Raj <raj.khem@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Segher Boessenkool <segher@kernel.crashing.org> Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dd665be upstream. gcc-6.0 warns about comparisons between two identical expressions, which is what we get in the floppy driver when writing to the FD_DOR register: drivers/block/floppy.c: In function 'set_dor': drivers/block/floppy.c:810:44: error: self-comparison always evaluates to true [-Werror=tautological-compare] fd_outb(newdor, FD_DOR); It would be nice to use a static inline function instead of the macro, to avoid the warning, but we cannot do that because the FD_DOR definition is incomplete at this point. Adding a cast to (u32) is a harmless way to shut up the warning, just not very nice. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit badbda5 upstream. pageblock_order can be (at least) an unsigned int or an unsigned long depending on the kernel config and architecture, so use max_t(unsigned long, ...) when comparing it. fixes these warnings: In file included from include/asm-generic/bug.h:13:0, from arch/powerpc/include/asm/bug.h:127, from include/linux/bug.h:4, from include/linux/mmdebug.h:4, from include/linux/mm.h:8, from include/linux/memblock.h:18, from mm/cma.c:28: mm/cma.c: In function 'cma_init_reserved_mem': include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ mm/cma.c:186:27: note: in expansion of macro 'max' alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order); ^ mm/cma.c: In function 'cma_declare_contiguous': include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ include/linux/kernel.h:747:9: note: in definition of macro 'max' typeof(y) _max2 = (y); ^ mm/cma.c:270:29: note: in expansion of macro 'max' (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order)); ^ include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ include/linux/kernel.h:747:21: note: in definition of macro 'max' typeof(y) _max2 = (y); ^ mm/cma.c:270:29: note: in expansion of macro 'max' (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order)); ^ [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20160526150748.5be38a4f@canb.auug.org.au Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 55c4b90 upstream. gcc-6 warns about a pointless loop in exynos_drm_subdrv_open: drivers/gpu/drm/exynos/exynos_drm_core.c: In function 'exynos_drm_subdrv_open': drivers/gpu/drm/exynos/exynos_drm_core.c:104:199: error: self-comparison always evaluates to false [-Werror=tautological-compare] list_for_each_entry_reverse(subdrv, &subdrv->list, list) { Here, the list_for_each_entry_reverse immediately terminates because the subdrv pointer is compared to itself as the loop end condition. If we were to take the current subdrv pointer as the start of the list (as we would do if list_for_each_entry_reverse() was not a macro), we would iterate backwards over the &exynos_drm_subdrv_list anchor, which would be even worse. Instead, we need to use list_for_each_entry_continue_reverse() to go back over each subdrv that was successfully opened until the first entry. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Inki Dae <inki.dae@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cfe02a8 upstream. When all subsystems are disabled, gcc notices that cgroup_subsys_enabled_key is a zero-length array and that any access to it must be out of bounds: In file included from ../include/linux/cgroup.h:19:0, from ../kernel/cgroup.c:31: ../kernel/cgroup.c: In function 'cgroup_add_cftypes': ../kernel/cgroup.c:261:53: error: array subscript is above array bounds [-Werror=array-bounds] return static_key_enabled(cgroup_subsys_enabled_key[ssid]); ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~ ../include/linux/jump_label.h:271:40: note: in definition of macro 'static_key_enabled' static_key_count((struct static_key *)x) > 0; \ ^ We should never call the function in this particular case, so this is not a bug. In order to silence the warning, this adds an explicit check for the CGROUP_SUBSYS_COUNT==0 case. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e3ebd89 upstream. The smc91x driver defines a macro that compares its argument to itself, apparently to get a true result while using its argument to avoid a warning about unused local variables. Unfortunately, this triggers a warning with gcc-6, as the comparison is obviously useless: drivers/net/ethernet/smsc/smc91x.c: In function 'smc_hardware_send_pkt': drivers/net/ethernet/smsc/smc91x.c:563:14: error: self-comparison always evaluates to true [-Werror=tautological-compare] if (!smc_special_trylock(&lp->lock, flags)) { This replaces the macro with another one that behaves similarly, with a cast to (void) to ensure the argument is used, and using a literal 'true' as its value. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 124a3d8 upstream. Newer versions of gcc warn about the use of __builtin_return_address() with a non-zero argument when "-Wall" is specified: kernel/trace/trace_irqsoff.c: In function ‘stop_critical_timings’: kernel/trace/trace_irqsoff.c:433:86: warning: calling ‘__builtin_return_address’ with a nonzero argument is unsafe [-Wframe-address] stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); [ .. repeats a few times for other similar cases .. ] It is true that a non-zero argument is somewhat dangerous, and we do not actually have very many uses of that in the kernel - but the ftrace code does use it, and as Stephen Rostedt says: "We are well aware of the danger of using __builtin_return_address() of > 0. In fact that's part of the reason for having the "thunk" code in x86 (See arch/x86/entry/thunk_{64,32}.S). [..] it adds extra frames when tracking irqs off sections, to prevent __builtin_return_address() from accessing bad areas. In fact the thunk_32.S states: 'Trampoline to trace irqs off. (otherwise CALLER_ADDR1 might crash)'." For now, __builtin_return_address() with a non-zero argument is the best we can do, and the warning is not helpful and can end up making people miss other warnings for real problems. So disable the frame-address warning on compilers that need it. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
…eader commit ecbfa8e upstream. scan_pool() does not mark the PEB for scrubing when bitflips are detected in the EC header of a free PEB (VID header region left to 0xff). Make sure we scrub the PEB in this case. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Fixes: dbb7d2a ("UBI: Add fastmap core") Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9d274c1 upstream. We have been seeing crashes on duplicate keys in btrfs_set_item_key_safe(): BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192) ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:2620! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs] With the following stack trace: #0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4) #1 btrfs_drop_extents (fs/btrfs/file.c:411:4) #2 log_one_extent (fs/btrfs/tree-log.c:4732:9) #3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9) #4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9) #5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8) #6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8) #7 btrfs_sync_file (fs/btrfs/file.c:1933:8) #8 vfs_fsync_range (fs/sync.c:188:9) #9 vfs_fsync (fs/sync.c:202:9) #10 do_fsync (fs/sync.c:212:9) #11 __do_sys_fdatasync (fs/sync.c:225:9) #12 __se_sys_fdatasync (fs/sync.c:223:1) #13 __x64_sys_fdatasync (fs/sync.c:223:1) #14 do_syscall_x64 (arch/x86/entry/common.c:52:14) #15 do_syscall_64 (arch/x86/entry/common.c:83:7) #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121) So we're logging a changed extent from fsync, which is splitting an extent in the log tree. But this split part already exists in the tree, triggering the BUG(). This is the state of the log tree at the time of the crash, dumped with drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py) to get more details than btrfs_print_leaf() gives us: >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"]) leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610 leaf 33439744 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 7 transid 9 size 8192 nbytes 8473563889606862198 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 204 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417704.983333333 (2024-05-22 15:41:44) mtime 1716417704.983333333 (2024-05-22 15:41:44) otime 17592186044416.000000000 (559444-03-08 01:40:16) item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13 index 195 namelen 3 name: 193 item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 4096 ram 12288 extent compression 0 (none) item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 4096 nr 8192 item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 ... So the real problem happened earlier: notice that items 4 (4k-12k) and 5 (8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and item 5 starts at i_size. Here is the state of the filesystem tree at the time of the crash: >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0)) >>> print_extent_buffer(nodes[0]) leaf 30425088 level 0 items 184 generation 9 owner 5 leaf 30425088 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da ... item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160 generation 7 transid 7 size 4096 nbytes 12288 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 6 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417703.220000000 (2024-05-22 15:41:43) mtime 1716417703.220000000 (2024-05-22 15:41:43) otime 1716417703.220000000 (2024-05-22 15:41:43) item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13 index 195 namelen 3 name: 193 item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 8192 ram 12288 extent compression 0 (none) item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 Item 5 in the log tree corresponds to item 183 in the filesystem tree, but nothing matches item 4. Furthermore, item 183 is the last item in the leaf. btrfs_log_prealloc_extents() is responsible for logging prealloc extents beyond i_size. It first truncates any previously logged prealloc extents that start beyond i_size. Then, it walks the filesystem tree and copies the prealloc extent items to the log tree. If it hits the end of a leaf, then it calls btrfs_next_leaf(), which unlocks the tree and does another search. However, while the filesystem tree is unlocked, an ordered extent completion may modify the tree. In particular, it may insert an extent item that overlaps with an extent item that was already copied to the log tree. This may manifest in several ways depending on the exact scenario, including an EEXIST error that is silently translated to a full sync, overlapping items in the log tree, or this crash. This particular crash is triggered by the following sequence of events: - Initially, the file has i_size=4k, a regular extent from 0-4k, and a prealloc extent beyond i_size from 4k-12k. The prealloc extent item is the last item in its B-tree leaf. - The file is fsync'd, which copies its inode item and both extent items to the log tree. - An xattr is set on the file, which sets the BTRFS_INODE_COPY_EVERYTHING flag. - The range 4k-8k in the file is written using direct I/O. i_size is extended to 8k, but the ordered extent is still in flight. - The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this calls copy_inode_items_to_log(), which calls btrfs_log_prealloc_extents(). - btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the filesystem tree. Since it starts before i_size, it skips it. Since it is the last item in its B-tree leaf, it calls btrfs_next_leaf(). - btrfs_next_leaf() unlocks the path. - The ordered extent completion runs, which converts the 4k-8k part of the prealloc extent to written and inserts the remaining prealloc part from 8k-12k. - btrfs_next_leaf() does a search and finds the new prealloc extent 8k-12k. - btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into the log tree. Note that it overlaps with the 4k-12k prealloc extent that was copied to the log tree by the first fsync. - fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k extent that was written. - This tries to drop the range 4k-8k in the log tree, which requires adjusting the start of the 4k-12k prealloc extent in the log tree to 8k. - btrfs_set_item_key_safe() sees that there is already an extent starting at 8k in the log tree and calls BUG(). Fix this by detecting when we're about to insert an overlapping file extent item in the log tree and truncating the part that would overlap. CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 22f0081 upstream. The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: #1: 98% system, 0% softirq, 3% hardirq, 0% idle #2: 98% system, 0% softirq, 3% hardirq, 0% idle #3: 98% system, 0% softirq, 3% hardirq, 0% idle #4: 98% system, 0% softirq, 3% hardirq, 0% idle #5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Greg KH <gregkh@linuxfoundation.org> Reported-and-tested-by: syzbot+5f996b83575ef4058638@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/00000000000073d54b061a6a1c65@google.com/ Reported-and-tested-by: syzbot+1b2abad17596ad03dcff@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/000000000000f45085061aa9b37e@google.com/ Fixes: 9908a32 ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu/ Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/29855215-52f5-4385-b058-91f42c2bee18@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit f1e197a ] trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 #1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 #2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 #3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 #4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ #7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context. Signed-off-by: Wander Lairson Costa <wander@redhat.com> Reported-by: Hu Chunyu <chuhu@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit af0cb3f ] Xiumei and Christoph reported the following lockdep splat, complaining of the qdisc root lock being taken twice: ============================================ WARNING: possible recursive locking detected 6.7.0-rc3+ #598 Not tainted -------------------------------------------- swapper/2/0 is trying to acquire lock: ffff888177190110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 but task is already holding lock: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sch->q.lock); lock(&sch->q.lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by swapper/2/0: #0: ffff888135a09d98 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x510 #1: ffffffffaaee5260 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x2c0/0x1ed0 #2: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 #3: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 #4: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 stack backtrace: CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.7.0-rc3+ #598 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x4a/0x80 __lock_acquire+0xfdd/0x3150 lock_acquire+0x1ca/0x540 _raw_spin_lock+0x34/0x80 __dev_queue_xmit+0x1560/0x2e70 tcf_mirred_act+0x82e/0x1260 [act_mirred] tcf_action_exec+0x161/0x480 tcf_classify+0x689/0x1170 prio_enqueue+0x316/0x660 [sch_prio] dev_qdisc_enqueue+0x46/0x220 __dev_queue_xmit+0x1615/0x2e70 ip_finish_output2+0x1218/0x1ed0 __ip_finish_output+0x8b3/0x1350 ip_output+0x163/0x4e0 igmp_ifc_timer_expire+0x44b/0x930 call_timer_fn+0x1a2/0x510 run_timer_softirq+0x54d/0x11a0 __do_softirq+0x1b3/0x88f irq_exit_rcu+0x18f/0x1e0 sysvec_apic_timer_interrupt+0x6f/0x90 </IRQ> This happens when TC does a mirred egress redirect from the root qdisc of device A to the root qdisc of device B. As long as these two locks aren't protecting the same qdisc, they can be acquired in chain: add a per-qdisc lockdep key to silence false warnings. This dynamic key should safely replace the static key we have in sch_htb: it was added to allow enqueueing to the device "direct qdisc" while still holding the qdisc root lock. v2: don't use static keys anymore in HTB direct qdiscs (thanks Eric Dumazet) CC: Maxim Mikityanskiy <maxim@isovalent.com> CC: Xiumei Mu <xmu@redhat.com> Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: multipath-tcp/mptcp_net-next#451 Signed-off-by: Davide Caratti <dcaratti@redhat.com> Link: https://lore.kernel.org/r/7dc06d6158f72053cf877a82e2a7a5bd23692faa.1713448007.git.dcaratti@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit cebae29 ] Shin'ichiro reported that when he's running fstests' test-case btrfs/167 on emulated zoned devices, he's seeing the following NULL pointer dereference in 'btrfs_zone_finish_endio()': Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f] CPU: 4 PID: 2332440 Comm: kworker/u80:15 Tainted: G W 6.10.0-rc2-kts+ #4 Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020 Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs] RSP: 0018:ffff88867f107a90 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff893e5534 RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088 RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed1081696028 R10: ffff88840b4b0143 R11: ffff88834dfff600 R12: ffff88840b4b0000 R13: 0000000000020000 R14: 0000000000000000 R15: ffff888530ad5210 FS: 0000000000000000(0000) GS:ffff888e3f800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f87223fff38 CR3: 00000007a7c6a002 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die_addr+0x46/0x70 ? exc_general_protection+0x14f/0x250 ? asm_exc_general_protection+0x26/0x30 ? do_raw_read_unlock+0x44/0x70 ? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs] btrfs_finish_one_ordered+0x5d9/0x19a0 [btrfs] ? __pfx_lock_release+0x10/0x10 ? do_raw_write_lock+0x90/0x260 ? __pfx_do_raw_write_lock+0x10/0x10 ? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs] ? _raw_write_unlock+0x23/0x40 ? btrfs_finish_ordered_zoned+0x5a9/0x850 [btrfs] ? lock_acquire+0x435/0x500 btrfs_work_helper+0x1b1/0xa70 [btrfs] ? __schedule+0x10a8/0x60b0 ? __pfx___might_resched+0x10/0x10 process_one_work+0x862/0x1410 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_process_one_work+0x10/0x10 ? assign_work+0x16c/0x240 worker_thread+0x5e6/0x1010 ? __pfx_worker_thread+0x10/0x10 kthread+0x2c3/0x3a0 ? trace_irq_enable.constprop.0+0xce/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Enabling CONFIG_BTRFS_ASSERT revealed the following assertion to trigger: assertion failed: !list_empty(&ordered->list), in fs/btrfs/zoned.c:1815 This indicates, that we're missing the checksums list on the ordered_extent. As btrfs/167 is doing a NOCOW write this is to be expected. Further analysis with drgn confirmed the assumption: >>> inode = prog.crashed_thread().stack_trace()[11]['ordered'].inode >>> btrfs_inode = drgn.container_of(inode, "struct btrfs_inode", \ "vfs_inode") >>> print(btrfs_inode.flags) (u32)1 As zoned emulation mode simulates conventional zones on regular devices, we cannot use zone-append for writing. But we're only attaching dummy checksums if we're doing a zone-append write. So for NOCOW zoned data writes on conventional zones, also attach a dummy checksum. Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Fixes: cbfce4c ("btrfs: optimize the logical to physical mapping for zoned writes") CC: Naohiro Aota <Naohiro.Aota@wdc.com> # 6.6+ Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 22f0081 upstream. The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: Freescale#1: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#2: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#3: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#4: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Greg KH <gregkh@linuxfoundation.org> Reported-and-tested-by: syzbot+5f996b83575ef4058638@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/00000000000073d54b061a6a1c65@google.com/ Reported-and-tested-by: syzbot+1b2abad17596ad03dcff@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/000000000000f45085061aa9b37e@google.com/ Fixes: 9908a32 ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu/ Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/29855215-52f5-4385-b058-91f42c2bee18@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit f1e197a ] trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 Freescale#1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 Freescale#2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 Freescale#3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 Freescale#4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ Freescale#7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context. Signed-off-by: Wander Lairson Costa <wander@redhat.com> Reported-by: Hu Chunyu <chuhu@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit be346c1 upstream. The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 Freescale#1 __crash_kexec at ffffffff8c1338fa Freescale#2 panic at ffffffff8c1d69b9 Freescale#3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] Freescale#4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] Freescale#5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] Freescale#6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] Freescale#7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] Freescale#8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] Freescale#9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] Freescale#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] Freescale#11 dio_complete at ffffffff8c2b9fa7 Freescale#12 do_blockdev_direct_IO at ffffffff8c2bc09f Freescale#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] Freescale#14 generic_file_direct_write at ffffffff8c1dcf14 Freescale#15 __generic_file_write_iter at ffffffff8c1dd07b Freescale#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] Freescale#17 aio_write at ffffffff8c2cc72e Freescale#18 kmem_cache_alloc at ffffffff8c248dde Freescale#19 do_io_submit at ffffffff8c2ccada Freescale#20 do_syscall_64 at ffffffff8c004984 Freescale#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Heming Zhao <heming.zhao@suse.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 59a931c ] If the driver uses a page pool, it creates a page pool with page_pool_create(). The reference count of page pool is 1 as default. A page pool will be destroyed only when a reference count reaches 0. page_pool_destroy() is used to destroy page pool, it decreases a reference count. When a page pool is destroyed, ->disconnect() is called, which is mem_allocator_disconnect(). This function internally acquires mutex_lock(). If the driver uses XDP, it registers a memory model with xdp_rxq_info_reg_mem_model(). The xdp_rxq_info_reg_mem_model() internally increases a page pool reference count if a memory model is a page pool. Now the reference count is 2. To destroy a page pool, the driver should call both page_pool_destroy() and xdp_unreg_mem_model(). The xdp_unreg_mem_model() internally calls page_pool_destroy(). Only page_pool_destroy() decreases a reference count. If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we will face an invalid wait context warning. Because xdp_unreg_mem_model() calls page_pool_destroy() with rcu_read_lock(). The page_pool_destroy() internally acquires mutex_lock(). Splat looks like: ============================= [ BUG: Invalid wait context ] 6.10.0-rc6+ Freescale#4 Tainted: G W ----------------------------- ethtool/1806 is trying to lock: ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150 other info that might help us debug this: context-{5:5} 3 locks held by ethtool/1806: stack backtrace: CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ Freescale#4 f916f41f172891c800f2fed Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 Call Trace: <TASK> dump_stack_lvl+0x7e/0xc0 __lock_acquire+0x1681/0x4de0 ? _printk+0x64/0xe0 ? __pfx_mark_lock.part.0+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x1b3/0x580 ? mem_allocator_disconnect+0x73/0x150 ? __wake_up_klogd.part.0+0x16/0xc0 ? __pfx_lock_acquire+0x10/0x10 ? dump_stack_lvl+0x91/0xc0 __mutex_lock+0x15c/0x1690 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_prb_read_valid+0x10/0x10 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_llist_add_batch+0x10/0x10 ? console_unlock+0x193/0x1b0 ? lockdep_hardirqs_on+0xbe/0x140 ? __pfx___mutex_lock+0x10/0x10 ? tick_nohz_tick_stopped+0x16/0x90 ? __irq_work_queue_local+0x1e5/0x330 ? irq_work_queue+0x39/0x50 ? __wake_up_klogd.part.0+0x79/0xc0 ? mem_allocator_disconnect+0x73/0x150 mem_allocator_disconnect+0x73/0x150 ? __pfx_mem_allocator_disconnect+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? rcu_is_watching+0x11/0xb0 page_pool_release+0x36e/0x6d0 page_pool_destroy+0xd7/0x440 xdp_unreg_mem_model+0x1a7/0x2a0 ? __pfx_xdp_unreg_mem_model+0x10/0x10 ? kfree+0x125/0x370 ? bnxt_free_ring.isra.0+0x2eb/0x500 ? bnxt_free_mem+0x5ac/0x2500 xdp_rxq_info_unreg+0x4a/0xd0 bnxt_free_mem+0x1356/0x2500 bnxt_close_nic+0xf0/0x3b0 ? __pfx_bnxt_close_nic+0x10/0x10 ? ethnl_parse_bit+0x2c6/0x6d0 ? __pfx___nla_validate_parse+0x10/0x10 ? __pfx_ethnl_parse_bit+0x10/0x10 bnxt_set_features+0x2a8/0x3e0 __netdev_update_features+0x4dc/0x1370 ? ethnl_parse_bitset+0x4ff/0x750 ? __pfx_ethnl_parse_bitset+0x10/0x10 ? __pfx___netdev_update_features+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? _raw_spin_unlock_irqrestore+0x42/0x70 ? __pm_runtime_resume+0x7d/0x110 ethnl_set_features+0x32d/0xa20 To fix this problem, it uses rhashtable_lookup_fast() instead of rhashtable_lookup() with rcu_read_lock(). Using xa without rcu_read_lock() here is safe. xa is freed by __xdp_mem_allocator_rcu_free() and this is called by call_rcu() of mem_xa_remove(). The mem_xa_remove() is called by page_pool_destroy() if a reference count reaches 0. The xa is already protected by the reference count mechanism well in the control plane. So removing rcu_read_lock() for page_pool_destroy() is safe. Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240712095116.3801586-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 86a41ea ] When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ Freescale#34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 Freescale#1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 Freescale#2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 Freescale#3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 Freescale#4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 Freescale#5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 Freescale#6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 Freescale#7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 Freescale#8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 Freescale#9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ Freescale#34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: gnault@redhat.com CC: cong.wang@bytedance.com Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 22f0081 upstream. The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: Freescale#1: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#2: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#3: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#4: 98% system, 0% softirq, 3% hardirq, 0% idle Freescale#5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Greg KH <gregkh@linuxfoundation.org> Reported-and-tested-by: syzbot+5f996b83575ef4058638@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/00000000000073d54b061a6a1c65@google.com/ Reported-and-tested-by: syzbot+1b2abad17596ad03dcff@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/000000000000f45085061aa9b37e@google.com/ Fixes: 9908a32 ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu/ Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/29855215-52f5-4385-b058-91f42c2bee18@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit f1e197a ] trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 Freescale#1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 Freescale#2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 Freescale#3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 Freescale#4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ Freescale#7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context. Signed-off-by: Wander Lairson Costa <wander@redhat.com> Reported-by: Hu Chunyu <chuhu@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit be346c1 upstream. The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 Freescale#1 __crash_kexec at ffffffff8c1338fa Freescale#2 panic at ffffffff8c1d69b9 Freescale#3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] Freescale#4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] Freescale#5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] Freescale#6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] Freescale#7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] Freescale#8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] Freescale#9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] Freescale#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] Freescale#11 dio_complete at ffffffff8c2b9fa7 Freescale#12 do_blockdev_direct_IO at ffffffff8c2bc09f Freescale#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] Freescale#14 generic_file_direct_write at ffffffff8c1dcf14 Freescale#15 __generic_file_write_iter at ffffffff8c1dd07b Freescale#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] Freescale#17 aio_write at ffffffff8c2cc72e Freescale#18 kmem_cache_alloc at ffffffff8c248dde Freescale#19 do_io_submit at ffffffff8c2ccada Freescale#20 do_syscall_64 at ffffffff8c004984 Freescale#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Heming Zhao <heming.zhao@suse.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 59a931c ] If the driver uses a page pool, it creates a page pool with page_pool_create(). The reference count of page pool is 1 as default. A page pool will be destroyed only when a reference count reaches 0. page_pool_destroy() is used to destroy page pool, it decreases a reference count. When a page pool is destroyed, ->disconnect() is called, which is mem_allocator_disconnect(). This function internally acquires mutex_lock(). If the driver uses XDP, it registers a memory model with xdp_rxq_info_reg_mem_model(). The xdp_rxq_info_reg_mem_model() internally increases a page pool reference count if a memory model is a page pool. Now the reference count is 2. To destroy a page pool, the driver should call both page_pool_destroy() and xdp_unreg_mem_model(). The xdp_unreg_mem_model() internally calls page_pool_destroy(). Only page_pool_destroy() decreases a reference count. If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we will face an invalid wait context warning. Because xdp_unreg_mem_model() calls page_pool_destroy() with rcu_read_lock(). The page_pool_destroy() internally acquires mutex_lock(). Splat looks like: ============================= [ BUG: Invalid wait context ] 6.10.0-rc6+ Freescale#4 Tainted: G W ----------------------------- ethtool/1806 is trying to lock: ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150 other info that might help us debug this: context-{5:5} 3 locks held by ethtool/1806: stack backtrace: CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ Freescale#4 f916f41f172891c800f2fed Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 Call Trace: <TASK> dump_stack_lvl+0x7e/0xc0 __lock_acquire+0x1681/0x4de0 ? _printk+0x64/0xe0 ? __pfx_mark_lock.part.0+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x1b3/0x580 ? mem_allocator_disconnect+0x73/0x150 ? __wake_up_klogd.part.0+0x16/0xc0 ? __pfx_lock_acquire+0x10/0x10 ? dump_stack_lvl+0x91/0xc0 __mutex_lock+0x15c/0x1690 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_prb_read_valid+0x10/0x10 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_llist_add_batch+0x10/0x10 ? console_unlock+0x193/0x1b0 ? lockdep_hardirqs_on+0xbe/0x140 ? __pfx___mutex_lock+0x10/0x10 ? tick_nohz_tick_stopped+0x16/0x90 ? __irq_work_queue_local+0x1e5/0x330 ? irq_work_queue+0x39/0x50 ? __wake_up_klogd.part.0+0x79/0xc0 ? mem_allocator_disconnect+0x73/0x150 mem_allocator_disconnect+0x73/0x150 ? __pfx_mem_allocator_disconnect+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? rcu_is_watching+0x11/0xb0 page_pool_release+0x36e/0x6d0 page_pool_destroy+0xd7/0x440 xdp_unreg_mem_model+0x1a7/0x2a0 ? __pfx_xdp_unreg_mem_model+0x10/0x10 ? kfree+0x125/0x370 ? bnxt_free_ring.isra.0+0x2eb/0x500 ? bnxt_free_mem+0x5ac/0x2500 xdp_rxq_info_unreg+0x4a/0xd0 bnxt_free_mem+0x1356/0x2500 bnxt_close_nic+0xf0/0x3b0 ? __pfx_bnxt_close_nic+0x10/0x10 ? ethnl_parse_bit+0x2c6/0x6d0 ? __pfx___nla_validate_parse+0x10/0x10 ? __pfx_ethnl_parse_bit+0x10/0x10 bnxt_set_features+0x2a8/0x3e0 __netdev_update_features+0x4dc/0x1370 ? ethnl_parse_bitset+0x4ff/0x750 ? __pfx_ethnl_parse_bitset+0x10/0x10 ? __pfx___netdev_update_features+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? _raw_spin_unlock_irqrestore+0x42/0x70 ? __pm_runtime_resume+0x7d/0x110 ethnl_set_features+0x32d/0xa20 To fix this problem, it uses rhashtable_lookup_fast() instead of rhashtable_lookup() with rcu_read_lock(). Using xa without rcu_read_lock() here is safe. xa is freed by __xdp_mem_allocator_rcu_free() and this is called by call_rcu() of mem_xa_remove(). The mem_xa_remove() is called by page_pool_destroy() if a reference count reaches 0. The xa is already protected by the reference count mechanism well in the control plane. So removing rcu_read_lock() for page_pool_destroy() is safe. Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240712095116.3801586-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 86a41ea ] When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ Freescale#34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 Freescale#1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 Freescale#2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 Freescale#3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 Freescale#4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 Freescale#5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 Freescale#6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 Freescale#7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 Freescale#8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 Freescale#9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ Freescale#34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: gnault@redhat.com CC: cong.wang@bytedance.com Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Sep 17, 2024
…play [ Upstream commit d182575 ] During inode logging (and log replay too), we are holding a transaction handle and we often need to call btrfs_iget(), which will read an inode from its subvolume btree if it's not loaded in memory and that results in allocating an inode with GFP_KERNEL semantics at the btrfs_alloc_inode() callback - and this may recurse into the filesystem in case we are under memory pressure and attempt to commit the current transaction, resulting in a deadlock since the logging (or log replay) task is holding a transaction handle open. Syzbot reported this with the following stack traces: WARNING: possible circular locking dependency detected 6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Not tainted ------------------------------------------------------ syz-executor.1/9919 is trying to acquire lock: ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3891 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3981 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 but task is already holding lock: ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> Freescale#3 (&ei->log_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 btrfs_log_inode_parent+0x8cb/0x2a90 fs/btrfs/tree-log.c:7079 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> Freescale#2 (btrfs_trans_num_extwriters){++++}-{0:0}: join_transaction+0x164/0xf40 fs/btrfs/transaction.c:315 start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700 btrfs_commit_super+0xa1/0x110 fs/btrfs/disk-io.c:4170 close_ctree+0xcb0/0xf90 fs/btrfs/disk-io.c:4324 generic_shutdown_super+0x159/0x3d0 fs/super.c:642 kill_anon_super+0x3a/0x60 fs/super.c:1226 btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2096 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super+0xde/0x100 fs/super.c:506 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> Freescale#1 (btrfs_trans_num_writers){++++}-{0:0}: __lock_release kernel/locking/lockdep.c:5468 [inline] lock_release+0x33e/0x6c0 kernel/locking/lockdep.c:5774 percpu_up_read include/linux/percpu-rwsem.h:99 [inline] __sb_end_write include/linux/fs.h:1650 [inline] sb_end_intwrite include/linux/fs.h:1767 [inline] __btrfs_end_transaction+0x5ca/0x920 fs/btrfs/transaction.c:1071 btrfs_commit_inode_delayed_inode+0x228/0x330 fs/btrfs/delayed-inode.c:1301 btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291 evict+0x2ed/0x6c0 fs/inode.c:667 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845 dput+0x1f/0x30 fs/dcache.c:835 ovl_stack_put+0x60/0x90 fs/overlayfs/util.c:132 ovl_destroy_inode+0xc6/0x190 fs/overlayfs/super.c:182 destroy_inode+0xc4/0x1b0 fs/inode.c:311 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 shrink_kill fs/dcache.c:1048 [inline] shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156 super_cache_scan+0x32a/0x550 fs/super.c:221 do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0xa87/0x1310 mm/shrinker.c:626 shrink_one+0x493/0x7c0 mm/vmscan.c:4790 shrink_many mm/vmscan.c:4851 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951 shrink_node mm/vmscan.c:5910 [inline] kswapd_shrink_node mm/vmscan.c:6720 [inline] balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411 alloc_inode+0x5d/0x230 fs/inode.c:261 iget5_locked fs/inode.c:1235 [inline] iget5_locked+0x1c9/0x2c0 fs/inode.c:1228 btrfs_iget_locked fs/btrfs/inode.c:5590 [inline] btrfs_iget_path fs/btrfs/inode.c:5607 [inline] btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636 add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline] copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928 btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592 log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline] btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718 btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline] btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 do_iter_readv_writev+0x504/0x780 fs/read_write.c:741 vfs_writev+0x36f/0xde0 fs/read_write.c:971 do_pwritev+0x1b2/0x260 fs/read_write.c:1072 __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline] __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline] __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: fs_reclaim --> btrfs_trans_num_extwriters --> &ei->log_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->log_mutex); lock(btrfs_trans_num_extwriters); lock(&ei->log_mutex); lock(fs_reclaim); *** DEADLOCK *** 7 locks held by syz-executor.1/9919: #0: ffff88802be20420 (sb_writers#23){.+.+}-{0:0}, at: do_pwritev+0x1b2/0x260 fs/read_write.c:1072 Freescale#1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline] Freescale#1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: btrfs_inode_lock+0xc8/0x110 fs/btrfs/inode.c:385 Freescale#2: ffff888065c0f778 (&ei->i_mmap_lock){++++}-{3:3}, at: btrfs_inode_lock+0xee/0x110 fs/btrfs/inode.c:388 Freescale#3: ffff88802be20610 (sb_internal#4){.+.+}-{0:0}, at: btrfs_sync_file+0x95b/0xe10 fs/btrfs/file.c:1952 Freescale#4: ffff8880546323f0 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290 Freescale#5: ffff888054632418 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290 Freescale#6: ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 stack backtrace: CPU: 2 PID: 9919 Comm: syz-executor.1 Not tainted 6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411 alloc_inode+0x5d/0x230 fs/inode.c:261 iget5_locked fs/inode.c:1235 [inline] iget5_locked+0x1c9/0x2c0 fs/inode.c:1228 btrfs_iget_locked fs/btrfs/inode.c:5590 [inline] btrfs_iget_path fs/btrfs/inode.c:5607 [inline] btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636 add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline] copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928 btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592 log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline] btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718 btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline] btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 do_iter_readv_writev+0x504/0x780 fs/read_write.c:741 vfs_writev+0x36f/0xde0 fs/read_write.c:971 do_pwritev+0x1b2/0x260 fs/read_write.c:1072 __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline] __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline] __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7334579 Code: b8 01 10 06 03 (...) RSP: 002b:00000000f5f265ac EFLAGS: 00000292 ORIG_RAX: 000000000000017b RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000200002c0 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Fix this by ensuring we are under a NOFS scope whenever we call btrfs_iget() during inode logging and log replay. Reported-by: syzbot+8576cfa84070dce4d59b@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/000000000000274a3a061abbd928@google.com/ Fixes: 712e36c ("btrfs: use GFP_KERNEL in btrfs_alloc_inode") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit be346c1 upstream. The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 Freescale#1 __crash_kexec at ffffffff8c1338fa Freescale#2 panic at ffffffff8c1d69b9 Freescale#3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] Freescale#4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] Freescale#5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] Freescale#6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] Freescale#7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] Freescale#8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] Freescale#9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] Freescale#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] Freescale#11 dio_complete at ffffffff8c2b9fa7 Freescale#12 do_blockdev_direct_IO at ffffffff8c2bc09f Freescale#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] Freescale#14 generic_file_direct_write at ffffffff8c1dcf14 Freescale#15 __generic_file_write_iter at ffffffff8c1dd07b Freescale#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] Freescale#17 aio_write at ffffffff8c2cc72e Freescale#18 kmem_cache_alloc at ffffffff8c248dde Freescale#19 do_io_submit at ffffffff8c2ccada Freescale#20 do_syscall_64 at ffffffff8c004984 Freescale#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Heming Zhao <heming.zhao@suse.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Sep 17, 2024
[ Upstream commit 59a931c ] If the driver uses a page pool, it creates a page pool with page_pool_create(). The reference count of page pool is 1 as default. A page pool will be destroyed only when a reference count reaches 0. page_pool_destroy() is used to destroy page pool, it decreases a reference count. When a page pool is destroyed, ->disconnect() is called, which is mem_allocator_disconnect(). This function internally acquires mutex_lock(). If the driver uses XDP, it registers a memory model with xdp_rxq_info_reg_mem_model(). The xdp_rxq_info_reg_mem_model() internally increases a page pool reference count if a memory model is a page pool. Now the reference count is 2. To destroy a page pool, the driver should call both page_pool_destroy() and xdp_unreg_mem_model(). The xdp_unreg_mem_model() internally calls page_pool_destroy(). Only page_pool_destroy() decreases a reference count. If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we will face an invalid wait context warning. Because xdp_unreg_mem_model() calls page_pool_destroy() with rcu_read_lock(). The page_pool_destroy() internally acquires mutex_lock(). Splat looks like: ============================= [ BUG: Invalid wait context ] 6.10.0-rc6+ Freescale#4 Tainted: G W ----------------------------- ethtool/1806 is trying to lock: ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150 other info that might help us debug this: context-{5:5} 3 locks held by ethtool/1806: stack backtrace: CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ Freescale#4 f916f41f172891c800f2fed Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 Call Trace: <TASK> dump_stack_lvl+0x7e/0xc0 __lock_acquire+0x1681/0x4de0 ? _printk+0x64/0xe0 ? __pfx_mark_lock.part.0+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x1b3/0x580 ? mem_allocator_disconnect+0x73/0x150 ? __wake_up_klogd.part.0+0x16/0xc0 ? __pfx_lock_acquire+0x10/0x10 ? dump_stack_lvl+0x91/0xc0 __mutex_lock+0x15c/0x1690 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_prb_read_valid+0x10/0x10 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_llist_add_batch+0x10/0x10 ? console_unlock+0x193/0x1b0 ? lockdep_hardirqs_on+0xbe/0x140 ? __pfx___mutex_lock+0x10/0x10 ? tick_nohz_tick_stopped+0x16/0x90 ? __irq_work_queue_local+0x1e5/0x330 ? irq_work_queue+0x39/0x50 ? __wake_up_klogd.part.0+0x79/0xc0 ? mem_allocator_disconnect+0x73/0x150 mem_allocator_disconnect+0x73/0x150 ? __pfx_mem_allocator_disconnect+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? rcu_is_watching+0x11/0xb0 page_pool_release+0x36e/0x6d0 page_pool_destroy+0xd7/0x440 xdp_unreg_mem_model+0x1a7/0x2a0 ? __pfx_xdp_unreg_mem_model+0x10/0x10 ? kfree+0x125/0x370 ? bnxt_free_ring.isra.0+0x2eb/0x500 ? bnxt_free_mem+0x5ac/0x2500 xdp_rxq_info_unreg+0x4a/0xd0 bnxt_free_mem+0x1356/0x2500 bnxt_close_nic+0xf0/0x3b0 ? __pfx_bnxt_close_nic+0x10/0x10 ? ethnl_parse_bit+0x2c6/0x6d0 ? __pfx___nla_validate_parse+0x10/0x10 ? __pfx_ethnl_parse_bit+0x10/0x10 bnxt_set_features+0x2a8/0x3e0 __netdev_update_features+0x4dc/0x1370 ? ethnl_parse_bitset+0x4ff/0x750 ? __pfx_ethnl_parse_bitset+0x10/0x10 ? __pfx___netdev_update_features+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? _raw_spin_unlock_irqrestore+0x42/0x70 ? __pm_runtime_resume+0x7d/0x110 ethnl_set_features+0x32d/0xa20 To fix this problem, it uses rhashtable_lookup_fast() instead of rhashtable_lookup() with rcu_read_lock(). Using xa without rcu_read_lock() here is safe. xa is freed by __xdp_mem_allocator_rcu_free() and this is called by call_rcu() of mem_xa_remove(). The mem_xa_remove() is called by page_pool_destroy() if a reference count reaches 0. The xa is already protected by the reference count mechanism well in the control plane. So removing rcu_read_lock() for page_pool_destroy() is safe. Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240712095116.3801586-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Sep 18, 2024
[ Upstream commit 86a41ea ] When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ Freescale#34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 Freescale#1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 Freescale#2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 Freescale#3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 Freescale#4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 Freescale#5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 Freescale#6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 Freescale#7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 Freescale#8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 Freescale#9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ Freescale#34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: gnault@redhat.com CC: cong.wang@bytedance.com Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
angolini
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Sep 18, 2024
[ Upstream commit b313a8c ] Lockdep reported a warning in Linux version 6.6: [ 414.344659] ================================ [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda Freescale#6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda Freescale#6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.356863] scsi_io_completion+0x177/0x1610 [ 414.357379] scsi_complete+0x12f/0x260 [ 414.357856] blk_complete_reqs+0xba/0xf0 [ 414.358338] __do_softirq+0x1b0/0x7a2 [ 414.358796] irq_exit_rcu+0x14b/0x1a0 [ 414.359262] sysvec_call_function_single+0xaf/0xc0 [ 414.359828] asm_sysvec_call_function_single+0x1a/0x20 [ 414.360426] default_idle+0x1e/0x30 [ 414.360873] default_idle_call+0x9b/0x1f0 [ 414.361390] do_idle+0x2d2/0x3e0 [ 414.361819] cpu_startup_entry+0x55/0x60 [ 414.362314] start_secondary+0x235/0x2b0 [ 414.362809] secondary_startup_64_no_verify+0x18f/0x19b [ 414.363413] irq event stamp: 428794 [ 414.363825] hardirqs last enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200 [ 414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50 [ 414.365629] softirqs last enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2 [ 414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0 [ 414.367425] other info that might help us debug this: [ 414.368194] Possible unsafe locking scenario: [ 414.368900] CPU0 [ 414.369225] ---- [ 414.369548] lock(&sbq->ws[i].wait); [ 414.370000] <Interrupt> [ 414.370342] lock(&sbq->ws[i].wait); [ 414.370802] *** DEADLOCK *** [ 414.371569] 5 locks held by kworker/u10:3/1152: [ 414.372088] #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0 [ 414.373180] Freescale#1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0 [ 414.374384] Freescale#2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00 [ 414.375342] Freescale#3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.376377] Freescale#4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0 [ 414.378607] stack backtrace: [ 414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda Freescale#6 [ 414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 414.381177] Workqueue: writeback wb_workfn (flush-253:0) [ 414.381805] Call Trace: [ 414.382136] <TASK> [ 414.382429] dump_stack_lvl+0x91/0xf0 [ 414.382884] mark_lock_irq+0xb3b/0x1260 [ 414.383367] ? __pfx_mark_lock_irq+0x10/0x10 [ 414.383889] ? stack_trace_save+0x8e/0xc0 [ 414.384373] ? __pfx_stack_trace_save+0x10/0x10 [ 414.384903] ? graph_lock+0xcf/0x410 [ 414.385350] ? save_trace+0x3d/0xc70 [ 414.385808] mark_lock.part.20+0x56d/0xa90 [ 414.386317] mark_held_locks+0xb0/0x110 [ 414.386791] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.387320] lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.387901] ? _raw_spin_unlock_irq+0x28/0x50 [ 414.388422] trace_hardirqs_on+0x58/0x100 [ 414.388917] _raw_spin_unlock_irq+0x28/0x50 [ 414.389422] __blk_mq_tag_busy+0x1d6/0x2a0 [ 414.389920] __blk_mq_get_driver_tag+0x761/0x9f0 [ 414.390899] blk_mq_dispatch_rq_list+0x1780/0x1ee0 [ 414.391473] ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10 [ 414.392070] ? sbitmap_get+0x2b8/0x450 [ 414.392533] ? __blk_mq_get_driver_tag+0x210/0x9f0 [ 414.393095] __blk_mq_sched_dispatch_requests+0xd99/0x1690 [ 414.393730] ? elv_attempt_insert_merge+0x1b1/0x420 [ 414.394302] ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10 [ 414.394970] ? lock_acquire+0x18d/0x460 [ 414.395456] ? blk_mq_run_hw_queue+0x637/0xa00 [ 414.395986] ? __pfx_lock_acquire+0x10/0x10 [ 414.396499] blk_mq_sched_dispatch_requests+0x109/0x190 [ 414.397100] blk_mq_run_hw_queue+0x66e/0xa00 [ 414.397616] blk_mq_flush_plug_list.part.17+0x614/0x2030 [ 414.398244] ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10 [ 414.398897] ? writeback_sb_inodes+0x241/0xcc0 [ 414.399429] blk_mq_flush_plug_list+0x65/0x80 [ 414.399957] __blk_flush_plug+0x2f1/0x530 [ 414.400458] ? __pfx___blk_flush_plug+0x10/0x10 [ 414.400999] blk_finish_plug+0x59/0xa0 [ 414.401467] wb_writeback+0x7cc/0x920 [ 414.401935] ? __pfx_wb_writeback+0x10/0x10 [ 414.402442] ? mark_held_locks+0xb0/0x110 [ 414.402931] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.403462] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.404062] wb_workfn+0x2b3/0xcf0 [ 414.404500] ? __pfx_wb_workfn+0x10/0x10 [ 414.404989] process_scheduled_works+0x432/0x13f0 [ 414.405546] ? __pfx_process_scheduled_works+0x10/0x10 [ 414.406139] ? do_raw_spin_lock+0x101/0x2a0 [ 414.406641] ? assign_work+0x19b/0x240 [ 414.407106] ? lock_is_held_type+0x9d/0x110 [ 414.407604] worker_thread+0x6f2/0x1160 [ 414.408075] ? __kthread_parkme+0x62/0x210 [ 414.408572] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.409168] ? __kthread_parkme+0x13c/0x210 [ 414.409678] ? __pfx_worker_thread+0x10/0x10 [ 414.410191] kthread+0x33c/0x440 [ 414.410602] ? __pfx_kthread+0x10/0x10 [ 414.411068] ret_from_fork+0x4d/0x80 [ 414.411526] ? __pfx_kthread+0x10/0x10 [ 414.411993] ret_from_fork_asm+0x1b/0x30 [ 414.412489] </TASK> When interrupt is turned on while a lock holding by spin_lock_irq it throws a warning because of potential deadlock. blk_mq_prep_dispatch_rq blk_mq_get_driver_tag __blk_mq_get_driver_tag __blk_mq_alloc_driver_tag blk_mq_tag_busy -> tag is already busy // failed to get driver tag blk_mq_mark_tag_wait spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait) __add_wait_queue(wq, wait) -> wait queue active blk_mq_get_driver_tag __blk_mq_tag_busy -> 1) tag must be idle, which means there can't be inflight IO spin_lock_irq(&tags->lock) -> lock B (hctx->tags) spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally -> 2) context must be preempt by IO interrupt to trigger deadlock. As shown above, the deadlock is not possible in theory, but the warning still need to be fixed. Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq. Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'") Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20240815024736.2040971-1-lilingfeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c3a5e3e ] When using cachefiles, lockdep may emit something similar to the circular locking dependency notice below. The problem appears to stem from the following: (1) Cachefiles manipulates xattrs on the files in its cache when called from ->writepages(). (2) The setxattr() and removexattr() system call handlers get the name (and value) from userspace after taking the sb_writers lock, putting accesses of the vma->vm_lock and mm->mmap_lock inside of that. (3) The afs filesystem uses a per-inode lock to prevent multiple revalidation RPCs and in writeback vs truncate to prevent parallel operations from deadlocking against the server on one side and local page locks on the other. Fix this by moving the getting of the name and value in {get,remove}xattr() outside of the sb_writers lock. This also has the minor benefits that we don't need to reget these in the event of a retry and we never try to take the sb_writers lock in the event we can't pull the name and value into the kernel. Alternative approaches that might fix this include moving the dispatch of a write to the cache off to a workqueue or trying to do without the validation lock in afs. Note that this might also affect other filesystems that use netfslib and/or cachefiles. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-build2+ torvalds#956 Not tainted ------------------------------------------------------ fsstress/6050 is trying to acquire lock: ffff888138fd82f0 (mapping.invalidate_lock#3){++++}-{3:3}, at: filemap_fault+0x26e/0x8b0 but task is already holding lock: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> Freescale#4 (&vma->vm_lock->lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_write+0x3b/0x50 vma_start_write+0x6b/0xa0 vma_link+0xcc/0x140 insert_vm_struct+0xb7/0xf0 alloc_bprm+0x2c1/0x390 kernel_execve+0x65/0x1a0 call_usermodehelper_exec_async+0x14d/0x190 ret_from_fork+0x24/0x40 ret_from_fork_asm+0x1a/0x30 -> Freescale#3 (&mm->mmap_lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 __might_fault+0x7c/0xb0 strncpy_from_user+0x25/0x160 removexattr+0x7f/0x100 __do_sys_fremovexattr+0x7e/0xb0 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> Freescale#2 (sb_writers#14){.+.+}-{0:0}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 percpu_down_read+0x3c/0x90 vfs_iocb_iter_write+0xe9/0x1d0 __cachefiles_write+0x367/0x430 cachefiles_issue_write+0x299/0x2f0 netfs_advance_write+0x117/0x140 netfs_write_folio.isra.0+0x5ca/0x6e0 netfs_writepages+0x230/0x2f0 afs_writepages+0x4d/0x70 do_writepages+0x1e8/0x3e0 filemap_fdatawrite_wbc+0x84/0xa0 __filemap_fdatawrite_range+0xa8/0xf0 file_write_and_wait_range+0x59/0x90 afs_release+0x10f/0x270 __fput+0x25f/0x3d0 __do_sys_close+0x43/0x70 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> Freescale#1 (&vnode->validate_lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_read+0x95/0x200 afs_writepages+0x37/0x70 do_writepages+0x1e8/0x3e0 filemap_fdatawrite_wbc+0x84/0xa0 filemap_invalidate_inode+0x167/0x1e0 netfs_unbuffered_write_iter+0x1bd/0x2d0 vfs_write+0x22e/0x320 ksys_write+0xbc/0x130 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (mapping.invalidate_lock#3){++++}-{3:3}: check_noncircular+0x119/0x160 check_prev_add+0x195/0x430 __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_read+0x95/0x200 filemap_fault+0x26e/0x8b0 __do_fault+0x57/0xd0 do_pte_missing+0x23b/0x320 __handle_mm_fault+0x2d4/0x320 handle_mm_fault+0x14f/0x260 do_user_addr_fault+0x2a2/0x500 exc_page_fault+0x71/0x90 asm_exc_page_fault+0x22/0x30 other info that might help us debug this: Chain exists of: mapping.invalidate_lock#3 --> &mm->mmap_lock --> &vma->vm_lock->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&vma->vm_lock->lock); lock(&mm->mmap_lock); lock(&vma->vm_lock->lock); rlock(mapping.invalidate_lock#3); *** DEADLOCK *** 1 lock held by fsstress/6050: #0: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250 stack backtrace: CPU: 0 PID: 6050 Comm: fsstress Not tainted 6.10.0-build2+ torvalds#956 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: <TASK> dump_stack_lvl+0x57/0x80 check_noncircular+0x119/0x160 ? queued_spin_lock_slowpath+0x4be/0x510 ? __pfx_check_noncircular+0x10/0x10 ? __pfx_queued_spin_lock_slowpath+0x10/0x10 ? mark_lock+0x47/0x160 ? init_chain_block+0x9c/0xc0 ? add_chain_block+0x84/0xf0 check_prev_add+0x195/0x430 __lock_acquire+0xaf0/0xd80 ? __pfx___lock_acquire+0x10/0x10 ? __lock_release.isra.0+0x13b/0x230 lock_acquire.part.0+0x103/0x280 ? filemap_fault+0x26e/0x8b0 ? __pfx_lock_acquire.part.0+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? lock_acquire+0xd7/0x120 down_read+0x95/0x200 ? filemap_fault+0x26e/0x8b0 ? __pfx_down_read+0x10/0x10 ? __filemap_get_folio+0x25/0x1a0 filemap_fault+0x26e/0x8b0 ? __pfx_filemap_fault+0x10/0x10 ? find_held_lock+0x7c/0x90 ? __pfx___lock_release.isra.0+0x10/0x10 ? __pte_offset_map+0x99/0x110 __do_fault+0x57/0xd0 do_pte_missing+0x23b/0x320 __handle_mm_fault+0x2d4/0x320 ? __pfx___handle_mm_fault+0x10/0x10 handle_mm_fault+0x14f/0x260 do_user_addr_fault+0x2a2/0x500 exc_page_fault+0x71/0x90 asm_exc_page_fault+0x22/0x30 Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/2136178.1721725194@warthog.procyon.org.uk cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Christian Brauner <brauner@kernel.org> cc: Jan Kara <jack@suse.cz> cc: Jeff Layton <jlayton@kernel.org> cc: Gao Xiang <xiang@kernel.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-erofs@lists.ozlabs.org cc: linux-fsdevel@vger.kernel.org [brauner: fix minor issues] Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 89a906d ] Floating point instructions in userspace can crash some arm kernels built with clang/LLD 17.0.6: BUG: unsupported FP instruction in kernel mode FPEXC == 0xc0000780 Internal error: Oops - undefined instruction: 0 [#1] ARM CPU: 0 PID: 196 Comm: vfp-reproducer Not tainted 6.10.0 #1 Hardware name: BCM2835 PC is at vfp_support_entry+0xc8/0x2cc LR is at do_undefinstr+0xa8/0x250 pc : [<c0101d50>] lr : [<c010a80c>] psr: a0000013 sp : dc8d1f68 ip : 60000013 fp : bedea19c r10: ec532b17 r9 : 00000010 r8 : 0044766c r7 : c0000780 r6 : ec532b17 r5 : c1c13800 r4 : dc8d1fb0 r3 : c10072c4 r2 : c0101c88 r1 : ec532b17 r0 : 0044766c Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 00c5387d Table: 0251c008 DAC: 00000051 Register r0 information: non-paged memory Register r1 information: vmalloc memory Register r2 information: non-slab/vmalloc memory Register r3 information: non-slab/vmalloc memory Register r4 information: 2-page vmalloc region Register r5 information: slab kmalloc-cg-2k Register r6 information: vmalloc memory Register r7 information: non-slab/vmalloc memory Register r8 information: non-paged memory Register r9 information: zero-size pointer Register r10 information: vmalloc memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process vfp-reproducer (pid: 196, stack limit = 0x61aaaf8b) Stack: (0xdc8d1f68 to 0xdc8d2000) 1f60: 0000081f b6f69300 0000000f c10073f4 c10072c4 dc8d1fb0 1f80: ec532b17 0c532b17 0044766c b6f9ccd8 00000000 c010a80c 00447670 60000010 1fa0: ffffffff c1c13800 00c5387d c0100f10 b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff 00000000 00000000 Call trace: [<c0101d50>] (vfp_support_entry) from [<c010a80c>] (do_undefinstr+0xa8/0x250) [<c010a80c>] (do_undefinstr) from [<c0100f10>] (__und_usr+0x70/0x80) Exception stack(0xdc8d1fb0 to 0xdc8d1ff8) 1fa0: b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff Code: 0a000061 e3877202 e594003c e3a09010 (eef16a10) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception in interrupt ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- This is a minimal userspace reproducer on a Raspberry Pi Zero W: #include <stdio.h> #include <math.h> int main(void) { double v = 1.0; printf("%fn", NAN + *(volatile double *)&v); return 0; } Another way to consistently trigger the oops is: calvin@raspberry-pi-zero-w ~$ python -c "import json" The bug reproduces only when the kernel is built with DYNAMIC_DEBUG=n, because the pr_debug() calls act as barriers even when not activated. This is the output from the same kernel source built with the same compiler and DYNAMIC_DEBUG=y, where the userspace reproducer works as expected: VFP: bounce: trigger ec532b17 fpexc c0000780 VFP: emulate: INST=0xee377b06 SCR=0x00000000 VFP: bounce: trigger eef1fa10 fpexc c0000780 VFP: emulate: INST=0xeeb40b40 SCR=0x00000000 VFP: raising exceptions 30000000 calvin@raspberry-pi-zero-w ~$ ./vfp-reproducer nan Crudely grepping for vmsr/vmrs instructions in the otherwise nearly idential text for vfp_support_entry() makes the problem obvious: vmlinux.llvm.good [0xc0101cb8] <+48>: vmrs r7, fpexc vmlinux.llvm.good [0xc0101cd8] <+80>: vmsr fpexc, r0 vmlinux.llvm.good [0xc0101d20] <+152>: vmsr fpexc, r7 vmlinux.llvm.good [0xc0101d38] <+176>: vmrs r4, fpexc vmlinux.llvm.good [0xc0101d6c] <+228>: vmrs r0, fpscr vmlinux.llvm.good [0xc0101dc4] <+316>: vmsr fpexc, r0 vmlinux.llvm.good [0xc0101dc8] <+320>: vmrs r0, fpsid vmlinux.llvm.good [0xc0101dcc] <+324>: vmrs r6, fpscr vmlinux.llvm.good [0xc0101e10] <+392>: vmrs r10, fpinst vmlinux.llvm.good [0xc0101eb8] <+560>: vmrs r10, fpinst2 vmlinux.llvm.bad [0xc0101cb8] <+48>: vmrs r7, fpexc vmlinux.llvm.bad [0xc0101cd8] <+80>: vmsr fpexc, r0 vmlinux.llvm.bad [0xc0101d20] <+152>: vmsr fpexc, r7 vmlinux.llvm.bad [0xc0101d30] <+168>: vmrs r0, fpscr vmlinux.llvm.bad [0xc0101d50] <+200>: vmrs r6, fpscr <== BOOM! vmlinux.llvm.bad [0xc0101d6c] <+228>: vmsr fpexc, r0 vmlinux.llvm.bad [0xc0101d70] <+232>: vmrs r0, fpsid vmlinux.llvm.bad [0xc0101da4] <+284>: vmrs r10, fpinst vmlinux.llvm.bad [0xc0101df8] <+368>: vmrs r4, fpexc vmlinux.llvm.bad [0xc0101e5c] <+468>: vmrs r10, fpinst2 I think LLVM's reordering is valid as the code is currently written: the compiler doesn't know the instructions have side effects in hardware. Fix by using "asm volatile" in fmxr() and fmrx(), so they cannot be reordered with respect to each other. The original compiler now produces working kernels on my hardware with DYNAMIC_DEBUG=n. This is the relevant piece of the diff of the vfp_support_entry() text, from the original oopsing kernel to a working kernel with this patch: vmrs r0, fpscr tst r0, #4096 bne 0xc0101d48 tst r0, #458752 beq 0xc0101ecc orr r7, r7, #536870912 ldr r0, [r4, #0x3c] mov r9, #16 -vmrs r6, fpscr orr r9, r9, #251658240 add r0, r0, #4 str r0, [r4, #0x3c] mvn r0, #159 sub r0, r0, #-1207959552 and r0, r7, r0 vmsr fpexc, r0 vmrs r0, fpsid +vmrs r6, fpscr and r0, r0, #983040 cmp r0, #65536 bne 0xc0101d88 Fixes: 4708fb0 ("ARM: vfp: Reimplement VFP exception entry in C code") Signed-off-by: Calvin Owens <calvin@wbinvd.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 44d1745 upstream. Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock on x86 due to a chain of locks and SRCU synchronizations. Translating the below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the fairness of r/w semaphores). CPU0 CPU1 CPU2 1 lock(&kvm->slots_lock); 2 lock(&vcpu->mutex); 3 lock(&kvm->srcu); 4 lock(cpu_hotplug_lock); 5 lock(kvm_lock); 6 lock(&kvm->slots_lock); 7 lock(cpu_hotplug_lock); 8 sync(&kvm->srcu); Note, there are likely more potential deadlocks in KVM x86, e.g. the same pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with __kvmclock_cpufreq_notifier(): cpuhp_cpufreq_online() | -> cpufreq_online() | -> cpufreq_gov_performance_limits() | -> __cpufreq_driver_target() | -> __target_index() | -> cpufreq_freq_transition_begin() | -> cpufreq_notify_transition() | -> ... __kvmclock_cpufreq_notifier() But, actually triggering such deadlocks is beyond rare due to the combination of dependencies and timings involved. E.g. the cpufreq notifier is only used on older CPUs without a constant TSC, mucking with the NX hugepage mitigation while VMs are running is very uncommon, and doing so while also onlining/offlining a CPU (necessary to generate contention on cpu_hotplug_lock) would be even more unusual. The most robust solution to the general cpu_hotplug_lock issue is likely to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq notifier doesn't to take kvm_lock. For now, settle for fixing the most blatant deadlock, as switching to an RCU-protected list is a much more involved change, but add a comment in locking.rst to call out that care needs to be taken when walking holding kvm_lock and walking vm_list. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-smp--c257535a0c9d-pip #330 Tainted: G S O ------------------------------------------------------ tee/35048 is trying to acquire lock: ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm] but task is already holding lock: ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (kvm_lock){+.+.}-{3:3}: __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 kvm_dev_ioctl+0x4fb/0xe50 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #2 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2e/0xb0 static_key_slow_inc+0x16/0x30 kvm_lapic_set_base+0x6a/0x1c0 [kvm] kvm_set_apic_base+0x8f/0xe0 [kvm] kvm_set_msr_common+0x9ae/0xf80 [kvm] vmx_set_msr+0xa54/0xbe0 [kvm_intel] __kvm_set_msr+0xb6/0x1a0 [kvm] kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm] kvm_vcpu_ioctl+0x485/0x5b0 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&kvm->srcu){.+.+}-{0:0}: __synchronize_srcu+0x44/0x1a0 synchronize_srcu_expedited+0x21/0x30 kvm_swap_active_memslots+0x110/0x1c0 [kvm] kvm_set_memslot+0x360/0x620 [kvm] __kvm_set_memory_region+0x27b/0x300 [kvm] kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm] kvm_vm_ioctl+0x295/0x650 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&kvm->slots_lock){+.+.}-{3:3}: __lock_acquire+0x15ef/0x2e30 lock_acquire+0xe0/0x260 __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 set_nx_huge_pages+0x179/0x1e0 [kvm] param_attr_store+0x93/0x100 module_attr_store+0x22/0x40 sysfs_kf_write+0x81/0xb0 kernfs_fop_write_iter+0x133/0x1d0 vfs_write+0x28d/0x380 ksys_write+0x70/0xe0 __x64_sys_write+0x1f/0x30 x64_sys_call+0x281b/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Cc: Chao Gao <chao.gao@intel.com> Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock") Cc: stable@vger.kernel.org Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 89a906d ] Floating point instructions in userspace can crash some arm kernels built with clang/LLD 17.0.6: BUG: unsupported FP instruction in kernel mode FPEXC == 0xc0000780 Internal error: Oops - undefined instruction: 0 [Freescale#1] ARM CPU: 0 PID: 196 Comm: vfp-reproducer Not tainted 6.10.0 Freescale#1 Hardware name: BCM2835 PC is at vfp_support_entry+0xc8/0x2cc LR is at do_undefinstr+0xa8/0x250 pc : [<c0101d50>] lr : [<c010a80c>] psr: a0000013 sp : dc8d1f68 ip : 60000013 fp : bedea19c r10: ec532b17 r9 : 00000010 r8 : 0044766c r7 : c0000780 r6 : ec532b17 r5 : c1c13800 r4 : dc8d1fb0 r3 : c10072c4 r2 : c0101c88 r1 : ec532b17 r0 : 0044766c Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 00c5387d Table: 0251c008 DAC: 00000051 Register r0 information: non-paged memory Register r1 information: vmalloc memory Register r2 information: non-slab/vmalloc memory Register r3 information: non-slab/vmalloc memory Register r4 information: 2-page vmalloc region Register r5 information: slab kmalloc-cg-2k Register r6 information: vmalloc memory Register r7 information: non-slab/vmalloc memory Register r8 information: non-paged memory Register r9 information: zero-size pointer Register r10 information: vmalloc memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process vfp-reproducer (pid: 196, stack limit = 0x61aaaf8b) Stack: (0xdc8d1f68 to 0xdc8d2000) 1f60: 0000081f b6f69300 0000000f c10073f4 c10072c4 dc8d1fb0 1f80: ec532b17 0c532b17 0044766c b6f9ccd8 00000000 c010a80c 00447670 60000010 1fa0: ffffffff c1c13800 00c5387d c0100f10 b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff 00000000 00000000 Call trace: [<c0101d50>] (vfp_support_entry) from [<c010a80c>] (do_undefinstr+0xa8/0x250) [<c010a80c>] (do_undefinstr) from [<c0100f10>] (__und_usr+0x70/0x80) Exception stack(0xdc8d1fb0 to 0xdc8d1ff8) 1fa0: b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff Code: 0a000061 e3877202 e594003c e3a09010 (eef16a10) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception in interrupt ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- This is a minimal userspace reproducer on a Raspberry Pi Zero W: #include <stdio.h> #include <math.h> int main(void) { double v = 1.0; printf("%fn", NAN + *(volatile double *)&v); return 0; } Another way to consistently trigger the oops is: calvin@raspberry-pi-zero-w ~$ python -c "import json" The bug reproduces only when the kernel is built with DYNAMIC_DEBUG=n, because the pr_debug() calls act as barriers even when not activated. This is the output from the same kernel source built with the same compiler and DYNAMIC_DEBUG=y, where the userspace reproducer works as expected: VFP: bounce: trigger ec532b17 fpexc c0000780 VFP: emulate: INST=0xee377b06 SCR=0x00000000 VFP: bounce: trigger eef1fa10 fpexc c0000780 VFP: emulate: INST=0xeeb40b40 SCR=0x00000000 VFP: raising exceptions 30000000 calvin@raspberry-pi-zero-w ~$ ./vfp-reproducer nan Crudely grepping for vmsr/vmrs instructions in the otherwise nearly idential text for vfp_support_entry() makes the problem obvious: vmlinux.llvm.good [0xc0101cb8] <+48>: vmrs r7, fpexc vmlinux.llvm.good [0xc0101cd8] <+80>: vmsr fpexc, r0 vmlinux.llvm.good [0xc0101d20] <+152>: vmsr fpexc, r7 vmlinux.llvm.good [0xc0101d38] <+176>: vmrs r4, fpexc vmlinux.llvm.good [0xc0101d6c] <+228>: vmrs r0, fpscr vmlinux.llvm.good [0xc0101dc4] <+316>: vmsr fpexc, r0 vmlinux.llvm.good [0xc0101dc8] <+320>: vmrs r0, fpsid vmlinux.llvm.good [0xc0101dcc] <+324>: vmrs r6, fpscr vmlinux.llvm.good [0xc0101e10] <+392>: vmrs r10, fpinst vmlinux.llvm.good [0xc0101eb8] <+560>: vmrs r10, fpinst2 vmlinux.llvm.bad [0xc0101cb8] <+48>: vmrs r7, fpexc vmlinux.llvm.bad [0xc0101cd8] <+80>: vmsr fpexc, r0 vmlinux.llvm.bad [0xc0101d20] <+152>: vmsr fpexc, r7 vmlinux.llvm.bad [0xc0101d30] <+168>: vmrs r0, fpscr vmlinux.llvm.bad [0xc0101d50] <+200>: vmrs r6, fpscr <== BOOM! vmlinux.llvm.bad [0xc0101d6c] <+228>: vmsr fpexc, r0 vmlinux.llvm.bad [0xc0101d70] <+232>: vmrs r0, fpsid vmlinux.llvm.bad [0xc0101da4] <+284>: vmrs r10, fpinst vmlinux.llvm.bad [0xc0101df8] <+368>: vmrs r4, fpexc vmlinux.llvm.bad [0xc0101e5c] <+468>: vmrs r10, fpinst2 I think LLVM's reordering is valid as the code is currently written: the compiler doesn't know the instructions have side effects in hardware. Fix by using "asm volatile" in fmxr() and fmrx(), so they cannot be reordered with respect to each other. The original compiler now produces working kernels on my hardware with DYNAMIC_DEBUG=n. This is the relevant piece of the diff of the vfp_support_entry() text, from the original oopsing kernel to a working kernel with this patch: vmrs r0, fpscr tst r0, #4096 bne 0xc0101d48 tst r0, #458752 beq 0xc0101ecc orr r7, r7, #536870912 ldr r0, [r4, #0x3c] mov r9, Freescale#16 -vmrs r6, fpscr orr r9, r9, #251658240 add r0, r0, Freescale#4 str r0, [r4, #0x3c] mvn r0, Freescale#159 sub r0, r0, #-1207959552 and r0, r7, r0 vmsr fpexc, r0 vmrs r0, fpsid +vmrs r6, fpscr and r0, r0, #983040 cmp r0, #65536 bne 0xc0101d88 Fixes: 4708fb0 ("ARM: vfp: Reimplement VFP exception entry in C code") Signed-off-by: Calvin Owens <calvin@wbinvd.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
angolini
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commit 44d1745 upstream. Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock on x86 due to a chain of locks and SRCU synchronizations. Translating the below lockdep splat, CPU1 Freescale#6 will wait on CPU0 Freescale#1, CPU0 Freescale#8 will wait on CPU2 Freescale#3, and CPU2 Freescale#7 will wait on CPU1 Freescale#4 (if there's a writer, due to the fairness of r/w semaphores). CPU0 CPU1 CPU2 1 lock(&kvm->slots_lock); 2 lock(&vcpu->mutex); 3 lock(&kvm->srcu); 4 lock(cpu_hotplug_lock); 5 lock(kvm_lock); 6 lock(&kvm->slots_lock); 7 lock(cpu_hotplug_lock); 8 sync(&kvm->srcu); Note, there are likely more potential deadlocks in KVM x86, e.g. the same pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with __kvmclock_cpufreq_notifier(): cpuhp_cpufreq_online() | -> cpufreq_online() | -> cpufreq_gov_performance_limits() | -> __cpufreq_driver_target() | -> __target_index() | -> cpufreq_freq_transition_begin() | -> cpufreq_notify_transition() | -> ... __kvmclock_cpufreq_notifier() But, actually triggering such deadlocks is beyond rare due to the combination of dependencies and timings involved. E.g. the cpufreq notifier is only used on older CPUs without a constant TSC, mucking with the NX hugepage mitigation while VMs are running is very uncommon, and doing so while also onlining/offlining a CPU (necessary to generate contention on cpu_hotplug_lock) would be even more unusual. The most robust solution to the general cpu_hotplug_lock issue is likely to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq notifier doesn't to take kvm_lock. For now, settle for fixing the most blatant deadlock, as switching to an RCU-protected list is a much more involved change, but add a comment in locking.rst to call out that care needs to be taken when walking holding kvm_lock and walking vm_list. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-smp--c257535a0c9d-pip Freescale#330 Tainted: G S O ------------------------------------------------------ tee/35048 is trying to acquire lock: ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm] but task is already holding lock: ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> Freescale#3 (kvm_lock){+.+.}-{3:3}: __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 kvm_dev_ioctl+0x4fb/0xe50 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> Freescale#2 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2e/0xb0 static_key_slow_inc+0x16/0x30 kvm_lapic_set_base+0x6a/0x1c0 [kvm] kvm_set_apic_base+0x8f/0xe0 [kvm] kvm_set_msr_common+0x9ae/0xf80 [kvm] vmx_set_msr+0xa54/0xbe0 [kvm_intel] __kvm_set_msr+0xb6/0x1a0 [kvm] kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm] kvm_vcpu_ioctl+0x485/0x5b0 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> Freescale#1 (&kvm->srcu){.+.+}-{0:0}: __synchronize_srcu+0x44/0x1a0 synchronize_srcu_expedited+0x21/0x30 kvm_swap_active_memslots+0x110/0x1c0 [kvm] kvm_set_memslot+0x360/0x620 [kvm] __kvm_set_memory_region+0x27b/0x300 [kvm] kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm] kvm_vm_ioctl+0x295/0x650 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&kvm->slots_lock){+.+.}-{3:3}: __lock_acquire+0x15ef/0x2e30 lock_acquire+0xe0/0x260 __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 set_nx_huge_pages+0x179/0x1e0 [kvm] param_attr_store+0x93/0x100 module_attr_store+0x22/0x40 sysfs_kf_write+0x81/0xb0 kernfs_fop_write_iter+0x133/0x1d0 vfs_write+0x28d/0x380 ksys_write+0x70/0xe0 __x64_sys_write+0x1f/0x30 x64_sys_call+0x281b/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Cc: Chao Gao <chao.gao@intel.com> Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock") Cc: stable@vger.kernel.org Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ac01c8c upstream. AddressSanitizer found a use-after-free bug in the symbol code which manifested as 'perf top' segfaulting. ==1238389==ERROR: AddressSanitizer: heap-use-after-free on address 0x60b00c48844b at pc 0x5650d8035961 bp 0x7f751aaecc90 sp 0x7f751aaecc80 READ of size 1 at 0x60b00c48844b thread T193 #0 0x5650d8035960 in _sort__sym_cmp util/sort.c:310 #1 0x5650d8043744 in hist_entry__cmp util/hist.c:1286 #2 0x5650d8043951 in hists__findnew_entry util/hist.c:614 #3 0x5650d804568f in __hists__add_entry util/hist.c:754 #4 0x5650d8045bf9 in hists__add_entry util/hist.c:772 #5 0x5650d8045df1 in iter_add_single_normal_entry util/hist.c:997 #6 0x5650d8043326 in hist_entry_iter__add util/hist.c:1242 #7 0x5650d7ceeefe in perf_event__process_sample /home/matt/src/linux/tools/perf/builtin-top.c:845 #8 0x5650d7ceeefe in deliver_event /home/matt/src/linux/tools/perf/builtin-top.c:1208 #9 0x5650d7fdb51b in do_flush util/ordered-events.c:245 #10 0x5650d7fdb51b in __ordered_events__flush util/ordered-events.c:324 #11 0x5650d7ced743 in process_thread /home/matt/src/linux/tools/perf/builtin-top.c:1120 #12 0x7f757ef1f133 in start_thread nptl/pthread_create.c:442 #13 0x7f757ef9f7db in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 When updating hist maps it's also necessary to update the hist symbol reference because the old one gets freed in map__put(). While this bug was probably introduced with 5c24b67 ("perf tools: Replace map->referenced & maps->removed_maps with map->refcnt"), the symbol objects were leaked until c087e94 ("perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL") was merged so the bug was masked. Fixes: c087e94 ("perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL") Reported-by: Yunzhao Li <yunzhao@cloudflare.com> Signed-off-by: Matt Fleming (Cloudflare) <matt@readmodwrite.com> Cc: Ian Rogers <irogers@google.com> Cc: kernel-team@cloudflare.com Cc: Namhyung Kim <namhyung@kernel.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: stable@vger.kernel.org # v5.13+ Link: https://lore.kernel.org/r/20240815142212.3834625-1-matt@readmodwrite.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9af2efe upstream. The fields in the hist_entry are filled on-demand which means they only have meaningful values when relevant sort keys are used. So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in the hist entry can be garbage. So it shouldn't access it unconditionally. I got a segfault, when I wanted to see cgroup profiles. $ sudo perf record -a --all-cgroups --synth=cgroup true $ sudo perf report -s cgroup Program received signal SIGSEGV, Segmentation fault. 0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48 48 return RC_CHK_ACCESS(map)->dso; (gdb) bt #0 0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48 #1 0x00005555557aa39b in map__load (map=0x0) at util/map.c:344 #2 0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385 #3 0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true) at util/hist.c:644 #4 0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0, block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761 #5 0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0, sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779 #6 0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015 #7 0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0) at util/hist.c:1260 #8 0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at builtin-report.c:334 #9 0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232 #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128, sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271 #11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354 #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132 #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245 #14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324 #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342 #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60) at util/session.c:780 #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688, file_path=0x555556038ff0 "perf.data") at util/session.c:1406 As you can see the entry->ms.map was NULL even if he->ms.map has a value. This is because 'sym' sort key is not given, so it cannot assume whether he->ms.sym and entry->ms.sym is the same. I only checked the 'sym' sort key here as it implies 'dso' behavior (so maps are the same). Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Matt Fleming <matt@readmodwrite.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20240826221045.1202305-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Oct 21, 2024
[ Upstream commit d1bc560 ] Add nested locking with I_MUTEX_XATTR subclass to avoid lockdep warning while handling xattr inode on file open syscall at ext4_xattr_inode_iget. Backtrace EXT4-fs (loop0): Ignoring removed oldalloc option ====================================================== WARNING: possible circular locking dependency detected 5.10.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor543/2794 is trying to acquire lock: ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline] ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425 but task is already holding lock: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ei->i_data_sem/3){++++}-{3:3}: lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566 down_write+0x93/0x180 kernel/locking/rwsem.c:1564 ext4_update_i_disksize fs/ext4/ext4.h:3267 [inline] ext4_xattr_inode_write fs/ext4/xattr.c:1390 [inline] ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1538 [inline] ext4_xattr_set_entry+0x331a/0x3d80 fs/ext4/xattr.c:1662 ext4_xattr_ibody_set+0x124/0x390 fs/ext4/xattr.c:2228 ext4_xattr_set_handle+0xc27/0x14e0 fs/ext4/xattr.c:2385 ext4_xattr_set+0x219/0x390 fs/ext4/xattr.c:2498 ext4_xattr_user_set+0xc9/0xf0 fs/ext4/xattr_user.c:40 __vfs_setxattr+0x404/0x450 fs/xattr.c:177 __vfs_setxattr_noperm+0x11d/0x4f0 fs/xattr.c:208 __vfs_setxattr_locked+0x1f9/0x210 fs/xattr.c:266 vfs_setxattr+0x112/0x2c0 fs/xattr.c:283 setxattr+0x1db/0x3e0 fs/xattr.c:548 path_setxattr+0x15a/0x240 fs/xattr.c:567 __do_sys_setxattr fs/xattr.c:582 [inline] __se_sys_setxattr fs/xattr.c:578 [inline] __x64_sys_setxattr+0xc5/0xe0 fs/xattr.c:578 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62 entry_SYSCALL_64_after_hwframe+0x61/0xcb -> #0 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566 down_write+0x93/0x180 kernel/locking/rwsem.c:1564 inode_lock include/linux/fs.h:782 [inline] ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline] ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline] __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562 notify_change+0xbb6/0xe60 fs/attr.c:435 do_truncate+0x1de/0x2c0 fs/open.c:64 handle_truncate fs/namei.c:2970 [inline] do_open fs/namei.c:3311 [inline] path_openat+0x29f3/0x3290 fs/namei.c:3425 do_filp_open+0x20b/0x450 fs/namei.c:3452 do_sys_openat2+0x124/0x460 fs/open.c:1207 do_sys_open fs/open.c:1223 [inline] __do_sys_open fs/open.c:1231 [inline] __se_sys_open fs/open.c:1227 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1227 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62 entry_SYSCALL_64_after_hwframe+0x61/0xcb other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->i_data_sem/3); lock(&ea_inode->i_rwsem#7/1); lock(&ei->i_data_sem/3); lock(&ea_inode->i_rwsem#7/1); *** DEADLOCK *** 5 locks held by syz-executor543/2794: #0: ffff888026fbc448 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x4a/0x2a0 fs/namespace.c:365 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline] #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: do_truncate+0x1cf/0x2c0 fs/open.c:62 #2: ffff8880215e3310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_setattr+0xec4/0x19c0 fs/ext4/inode.c:5519 #3: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline] #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5938 [inline] #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x4fb/0x810 fs/ext4/inode.c:6018 stack backtrace: CPU: 1 PID: 2794 Comm: syz-executor543 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x177/0x211 lib/dump_stack.c:118 print_circular_bug+0x146/0x1b0 kernel/locking/lockdep.c:2002 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566 down_write+0x93/0x180 kernel/locking/rwsem.c:1564 inode_lock include/linux/fs.h:782 [inline] ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline] ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline] __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562 notify_change+0xbb6/0xe60 fs/attr.c:435 do_truncate+0x1de/0x2c0 fs/open.c:64 handle_truncate fs/namei.c:2970 [inline] do_open fs/namei.c:3311 [inline] path_openat+0x29f3/0x3290 fs/namei.c:3425 do_filp_open+0x20b/0x450 fs/namei.c:3452 do_sys_openat2+0x124/0x460 fs/open.c:1207 do_sys_open fs/open.c:1223 [inline] __do_sys_open fs/open.c:1231 [inline] __se_sys_open fs/open.c:1227 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1227 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f0cde4ea229 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd81d1c978 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0030656c69662f30 RCX: 00007f0cde4ea229 RDX: 0000000000000089 RSI: 00000000000a0a00 RDI: 00000000200001c0 RBP: 2f30656c69662f2e R08: 0000000000208000 R09: 0000000000208000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd81d1c9c0 R13: 00007ffd81d1ca00 R14: 0000000000080000 R15: 0000000000000003 EXT4-fs error (device loop0): ext4_expand_extra_isize_ea:2730: inode #13: comm syz-executor543: corrupted in-inode xattr Signed-off-by: Wojciech Gładysz <wojciech.gladysz@infogain.com> Link: https://patch.msgid.link/20240801143827.19135-1-wojciech.gladysz@infogain.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit a848c29 ] On the node of an NFS client, some files saved in the mountpoint of the NFS server were copied to another location of the same NFS server. Accidentally, the nfs42_complete_copies() got a NULL-pointer dereference crash with the following syslog: [232064.838881] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116 [232064.839360] NFSv4: state recovery failed for open file nfs/pvc-12b5200d-cd0f-46a3-b9f0-af8f4fe0ef64.qcow2, error = -116 [232066.588183] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 [232066.588586] Mem abort info: [232066.588701] ESR = 0x0000000096000007 [232066.588862] EC = 0x25: DABT (current EL), IL = 32 bits [232066.589084] SET = 0, FnV = 0 [232066.589216] EA = 0, S1PTW = 0 [232066.589340] FSC = 0x07: level 3 translation fault [232066.589559] Data abort info: [232066.589683] ISV = 0, ISS = 0x00000007 [232066.589842] CM = 0, WnR = 0 [232066.589967] user pgtable: 64k pages, 48-bit VAs, pgdp=00002000956ff400 [232066.590231] [0000000000000058] pgd=08001100ae100003, p4d=08001100ae100003, pud=08001100ae100003, pmd=08001100b3c00003, pte=0000000000000000 [232066.590757] Internal error: Oops: 96000007 [#1] SMP [232066.590958] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm vhost_net vhost vhost_iotlb tap tun ipt_rpfilter xt_multiport ip_set_hash_ip ip_set_hash_net xfrm_interface xfrm6_tunnel tunnel4 tunnel6 esp4 ah4 wireguard libcurve25519_generic veth xt_addrtype xt_set nf_conntrack_netlink ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_bitmap_port ip_set_hash_ipport dummy ip_set ip_vs_sh ip_vs_wrr ip_vs_rr ip_vs iptable_filter sch_ingress nfnetlink_cttimeout vport_gre ip_gre ip_tunnel gre vport_geneve geneve vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nf_conncount dm_round_robin dm_service_time dm_multipath xt_nat xt_MASQUERADE nft_chain_nat nf_nat xt_mark xt_conntrack xt_comment nft_compat nft_counter nf_tables nfnetlink ocfs2 ocfs2_nodemanager ocfs2_stackglue iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_ssif nbd overlay 8021q garp mrp bonding tls rfkill sunrpc ext4 mbcache jbd2 [232066.591052] vfat fat cas_cache cas_disk ses enclosure scsi_transport_sas sg acpi_ipmi ipmi_si ipmi_devintf ipmi_msghandler ip_tables vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio dm_mirror dm_region_hash dm_log dm_mod nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc fuse xfs libcrc32c ast drm_vram_helper qla2xxx drm_kms_helper syscopyarea crct10dif_ce sysfillrect ghash_ce sysimgblt sha2_ce fb_sys_fops cec sha256_arm64 sha1_ce drm_ttm_helper ttm nvme_fc igb sbsa_gwdt nvme_fabrics drm nvme_core i2c_algo_bit i40e scsi_transport_fc megaraid_sas aes_neon_bs [232066.596953] CPU: 6 PID: 4124696 Comm: 10.253.166.125- Kdump: loaded Not tainted 5.15.131-9.cl9_ocfs2.aarch64 #1 [232066.597356] Hardware name: Great Wall .\x93\x8e...RF6260 V5/GWMSSE2GL1T, BIOS T656FBE_V3.0.18 2024-01-06 [232066.597721] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [232066.598034] pc : nfs4_reclaim_open_state+0x220/0x800 [nfsv4] [232066.598327] lr : nfs4_reclaim_open_state+0x12c/0x800 [nfsv4] [232066.598595] sp : ffff8000f568fc70 [232066.598731] x29: ffff8000f568fc70 x28: 0000000000001000 x27: ffff21003db33000 [232066.599030] x26: ffff800005521ae0 x25: ffff0100f98fa3f0 x24: 0000000000000001 [232066.599319] x23: ffff800009920008 x22: ffff21003db33040 x21: ffff21003db33050 [232066.599628] x20: ffff410172fe9e40 x19: ffff410172fe9e00 x18: 0000000000000000 [232066.599914] x17: 0000000000000000 x16: 0000000000000004 x15: 0000000000000000 [232066.600195] x14: 0000000000000000 x13: ffff800008e685a8 x12: 00000000eac0c6e6 [232066.600498] x11: 0000000000000000 x10: 0000000000000008 x9 : ffff8000054e5828 [232066.600784] x8 : 00000000ffffffbf x7 : 0000000000000001 x6 : 000000000a9eb14a [232066.601062] x5 : 0000000000000000 x4 : ffff70ff8a14a800 x3 : 0000000000000058 [232066.601348] x2 : 0000000000000001 x1 : 54dce46366daa6c6 x0 : 0000000000000000 [232066.601636] Call trace: [232066.601749] nfs4_reclaim_open_state+0x220/0x800 [nfsv4] [232066.601998] nfs4_do_reclaim+0x1b8/0x28c [nfsv4] [232066.602218] nfs4_state_manager+0x928/0x10f0 [nfsv4] [232066.602455] nfs4_run_state_manager+0x78/0x1b0 [nfsv4] [232066.602690] kthread+0x110/0x114 [232066.602830] ret_from_fork+0x10/0x20 [232066.602985] Code: 1400000d f9403f20 f9402e61 91016003 (f9402c00) [232066.603284] SMP: stopping secondary CPUs [232066.606936] Starting crashdump kernel... [232066.607146] Bye! Analysing the vmcore, we know that nfs4_copy_state listed by destination nfs_server->ss_copies was added by the field copies in handle_async_copy(), and we found a waiting copy process with the stack as: PID: 3511963 TASK: ffff710028b47e00 CPU: 0 COMMAND: "cp" #0 [ffff8001116ef740] __switch_to at ffff8000081b92f4 #1 [ffff8001116ef760] __schedule at ffff800008dd0650 #2 [ffff8001116ef7c0] schedule at ffff800008dd0a00 #3 [ffff8001116ef7e0] schedule_timeout at ffff800008dd6aa0 #4 [ffff8001116ef860] __wait_for_common at ffff800008dd166c #5 [ffff8001116ef8e0] wait_for_completion_interruptible at ffff800008dd1898 #6 [ffff8001116ef8f0] handle_async_copy at ffff8000055142f4 [nfsv4] #7 [ffff8001116ef970] _nfs42_proc_copy at ffff8000055147c8 [nfsv4] #8 [ffff8001116efa80] nfs42_proc_copy at ffff800005514cf0 [nfsv4] #9 [ffff8001116efc50] __nfs4_copy_file_range.constprop.0 at ffff8000054ed694 [nfsv4] The NULL-pointer dereference was due to nfs42_complete_copies() listed the nfs_server->ss_copies by the field ss_copies of nfs4_copy_state. So the nfs4_copy_state address ffff0100f98fa3f0 was offset by 0x10 and the data accessed through this pointer was also incorrect. Generally, the ordered list nfs4_state_owner->so_states indicate open(O_RDWR) or open(O_WRITE) states are reclaimed firstly by nfs4_reclaim_open_state(). When destination state reclaim is failed with NFS_STATE_RECOVERY_FAILED and copies are not deleted in nfs_server->ss_copies, the source state may be passed to the nfs42_complete_copies() process earlier, resulting in this crash scene finally. To solve this issue, we add a list_head nfs_server->ss_src_copies for a server-to-server copy specially. Fixes: 0e65a32 ("NFS: handle source server reboot") Signed-off-by: Yanjun Zhang <zhangyanjun@cestc.cn> Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 3d04139 upstream. Syzkaller reported a lockdep splat: ============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted -------------------------------------------- syz-executor364/5113 is trying to acquire lock: ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 but task is already holding lock: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-slock-AF_INET); lock(k-slock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor364/5113: #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806 #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228 #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232 #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 stack backtrace: CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279 subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874 tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853 tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline] tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729 tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x214/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04fb13a6b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9 RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004 RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300 </TASK> As noted by Cong Wang, the splat is false positive, but the code path leading to the report is an unexpected one: a client is attempting an MPC handshake towards the in-kernel listener created by the in-kernel PM for a port based signal endpoint. Such connection will be never accepted; many of them can make the listener queue full and preventing the creation of MPJ subflow via such listener - its intended role. Explicitly detect this scenario at initial-syn time and drop the incoming MPC request. Fixes: 1729cf1 ("mptcp: create the listening socket for new port") Cc: stable@vger.kernel.org Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e Cc: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20241014-net-mptcp-mpc-port-endp-v2-1-7faea8e6b6ae@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> [ Conflicts in mib.[ch], because commit 6982826 ("mptcp: fallback to TCP after SYN+MPC drops"), and commit 27069e7 ("mptcp: disable active MPTCP in case of blackhole") are linked to new features, not available in this version. Resolving the conflicts is easy, simply adding the new lines declaring the new "endpoint attempt" MIB entry. ] Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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just merged longterm supported branch 4.4.38 into linux-fslc 4.4.x branch