Rpk v4.14 meltdown spectre mitigations #4

ardbiesheuvel · 2018-01-05T22:57:57Z

This is a backport to RPK/v4.14 of the KPTI patches that are queued for v4.16 in the arm64 tree, as well as the HYP branch predictor hardening patches that were sent to LAKML over the past week, including one for Falkor that is built on top of the new BP hardening framework.

Note that this makes KPTI dependent on a newly introduced ID register that defaults to 'affected' for all CPUs, including ones that are known not to be affected by the variant that KPTI addresses (Meltdown). This is in line with the upstream, and KPTI can still be disabled both at build time and at runtime.

In preparation for unmapping the kernel whilst running in userspace, make the kernel mappings non-global so we can avoid expensive TLB invalidation on kernel exit to userspace. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

We're about to rework the way ASIDs are allocated, switch_mm is implemented and low-level kernel entry/exit is handled, so keep the ARM64_SW_TTBR0_PAN code out of the way whilst we do the heavy lifting. It will be re-enabled in a subsequent patch. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

In preparation for mapping kernelspace and userspace with different ASIDs, move the ASID to TTBR1 and update switch_mm to context-switch TTBR0 via an invalid mapping (the zero page). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

The pre_ttbr0_update_workaround hook is called prior to context-switching TTBR0 because Falkor erratum E1003 can cause TLB allocation with the wrong ASID if both the ASID and the base address of the TTBR are updated at the same time. With the ASID sitting safely in TTBR1, we no longer update things atomically, so we can remove the pre_ttbr0_update_workaround macro as it's no longer required. The erratum infrastructure and documentation is left around for #E1003, as it will be required by the entry trampoline code in a future patch. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

The post_ttbr0_update_workaround hook applies to any change to TTBRx_EL1. Since we're using TTBR1 for the ASID, rename the hook to make it clearer as to what it's doing. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

With the ASID now installed in TTBR1, we can re-enable ARM64_SW_TTBR0_PAN by ensuring that we switch to a reserved ASID of zero when disabling user access and restore the active user ASID on the uaccess enable path. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

In preparation for separate kernel/user ASIDs, allocate them in pairs for each mm_struct. The bottom bit distinguishes the two: if it is set, then the ASID will map only userspace. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

In order for code such as TLB invalidation to operate efficiently when the decision to map the kernel at EL0 is determined at runtime, this patch introduces a helper function, arm64_kernel_unmapped_at_el0, to determine whether or not the kernel is mapped whilst running in userspace. Currently, this just reports the value of CONFIG_UNMAP_KERNEL_AT_EL0, but will later be hooked up to a fake CPU capability using a static key. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Since an mm has both a kernel and a user ASID, we need to ensure that broadcast TLB maintenance targets both address spaces so that things like CoW continue to work with the uaccess primitives in the kernel. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

To allow unmapping of the kernel whilst running at EL0, we need to point the exception vectors at an entry trampoline that can map/unmap the kernel on entry/exit respectively. This patch adds the trampoline page, although it is not yet plugged into the vector table and is therefore unused. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

The exception entry trampoline needs to be mapped at the same virtual address in both the trampoline page table (which maps nothing else) and also the kernel page table, so that we can swizzle TTBR1_EL1 on exceptions from and return to EL0. This patch maps the trampoline at a fixed virtual address in the fixmap area of the kernel virtual address space, which allows the kernel proper to be randomized with respect to the trampoline when KASLR is enabled. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

We will need to treat exceptions from EL0 differently in kernel_ventry, so rework the macro to take the exception level as an argument and construct the branch target using that. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Hook up the entry trampoline to our exception vectors so that all exceptions from and returns to EL0 go via the trampoline, which swizzles the vector base register accordingly. Transitioning to and from the kernel clobbers x30, so we use tpidrro_el0 and far_el1 as scratch registers for native tasks. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

We rely on an atomic swizzling of TTBR1 when transitioning from the entry trampoline to the kernel proper on an exception. We can't rely on this atomicity in the face of Falkor erratum #E1003, so on affected cores we can issue a TLB invalidation to invalidate the walk cache prior to jumping into the kernel. There is still the possibility of a TLB conflict here due to conflicting walk cache entries prior to the invalidation, but this doesn't appear to be the case on these CPUs in practice. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

When unmapping the kernel at EL0, we use tpidrro_el0 as a scratch register during exception entry from native tasks and subsequently zero it in the kernel_ventry macro. We can therefore avoid zeroing tpidrro_el0 in the context-switch path for native tasks using the entry trampoline. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Allow explicit disabling of the entry trampoline on the kernel command line (kpti=off) by adding a fake CPU feature (ARM64_UNMAP_KERNEL_AT_EL0) that can be used to toggle the alternative sequences in our entry code and avoid use of the trampoline altogether if desired. This also allows us to make use of a static key in arm64_kernel_unmapped_at_el0(). Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Add a Kconfig entry to control use of the entry trampoline, which allows us to unmap the kernel whilst running in userspace and improve the robustness of KASLR. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

There are now a handful of open-coded masks to extract the ASID from a TTBR value, so introduce a TTBR_ASID_MASK and use that instead. Suggested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

The literal pool entry for identifying the vectors base is the only piece of information in the trampoline page that identifies the true location of the kernel. This patch moves it into a page-aligned region of the .rodata section and maps this adjacent to the trampoline text via an additional fixmap entry, which protects against any accidental leakage of the trampoline contents. Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Laura Abbott <labbott@redhat.com> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Speculation attacks against the entry trampoline can potentially resteer the speculative instruction stream through the indirect branch and into arbitrary gadgets within the kernel. This patch defends against these attacks by forcing a misprediction through the return stack: a dummy BL instruction loads an entry into the stack, so that the predicted program flow of the subsequent RET instruction is to a branch-to-self instruction which is finally resolved as a branch to the kernel vectors with speculation suppressed. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Although CONFIG_UNMAP_KERNEL_AT_EL0 does make KASLR more robust, it's actually more useful as a mitigation against speculation attacks that can leak arbitrary kernel data to userspace through speculation. Reword the Kconfig help message to reflect this, and make the option depend on EXPERT so that it is on by default for the majority of users. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

For non-KASLR kernels where the KPTI behaviour has not been overridden on the command line we can use ID_AA64PFR0_EL1.CSV3 to determine whether or not we should unmap the kernel whilst running at EL0. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

In order to invoke the CPU capability ->matches callback from the ->enable callback for applying local-CPU workarounds, we need a handle on the capability structure. This patch passes a pointer to the capability structure to the ->enable callback. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Entry into recent versions of ARM Trusted Firmware will invalidate the CPU branch predictor state in order to protect against aliasing attacks. This patch exposes the PSCI "VERSION" function via psci_ops, so that it can be invoked outside of the PSCI driver where necessary. Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

We will soon need to invoke a CPU-specific function pointer after changing page tables, so move post_ttbr_update_workaround out into C code to make this possible. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

…ttacks Aliasing attacks against CPU branch predictors can allow an attacker to redirect speculative control flow on some CPUs and potentially divulge information from one context to another. This patch adds initial skeleton code behind a new Kconfig option to enable implementation-specific mitigations against these attacks for CPUs that are affected. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Now that we have per-CPU vectors, let's plug then in the KVM/arm64 code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

For those CPUs that require PSCI to perform a BP invalidation, going all the way to the PSCI code for not much is a waste of precious cycles. Let's terminate that call as early as possible. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Hook up MIDR values for the Cortex-A72 and Cortex-A75 CPUs, since they will soon need MIDR matches for hardening the branch predictor. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Cortex-A57, A72, A73 and A75 are susceptible to branch predictor aliasing and can theoretically be attacked by malicious code. This patch implements a PSCI-based mitigation for these CPUs when available. The call into firmware will invalidate the branch predictor state, preventing any malicious entries from affecting other victim contexts. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> [ardb: fix incorrect stack offset in __psci_hyp_bp_inval_start()] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

commit 9952509 upstream. Avoid that KASAN reports the following: BUG: KASAN: use-after-free in srpt_close_ch+0x4f/0x1b0 [ib_srpt] Read of size 4 at addr ffff880151180cb8 by task check/4681 CPU: 15 PID: 4681 Comm: check Not tainted 4.18.0-rc2-dbg+ #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 Call Trace: dump_stack+0xa4/0xf5 print_address_description+0x6f/0x270 kasan_report+0x241/0x360 __asan_load4+0x78/0x80 srpt_close_ch+0x4f/0x1b0 [ib_srpt] srpt_set_enabled+0xf7/0x1e0 [ib_srpt] srpt_tpg_enable_store+0xb8/0x120 [ib_srpt] configfs_write_file+0x14e/0x1d0 [configfs] __vfs_write+0xd2/0x3b0 vfs_write+0x101/0x270 ksys_write+0xab/0x120 __x64_sys_write+0x43/0x50 do_syscall_64+0x77/0x230 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: aaf45bd ("IB/srpt: Detect session shutdown reliably") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: <stable@vger.kernel.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 14d15c2 upstream. BUG: KASAN: use-after-free in srpt_set_enabled+0x1a9/0x1e0 [ib_srpt] Read of size 4 at addr ffff8801269d23f8 by task check/29726 CPU: 4 PID: 29726 Comm: check Not tainted 4.18.0-rc2-dbg+ #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 Call Trace: dump_stack+0xa4/0xf5 print_address_description+0x6f/0x270 kasan_report+0x241/0x360 __asan_load4+0x78/0x80 srpt_set_enabled+0x1a9/0x1e0 [ib_srpt] srpt_tpg_enable_store+0xb8/0x120 [ib_srpt] configfs_write_file+0x14e/0x1d0 [configfs] __vfs_write+0xd2/0x3b0 vfs_write+0x101/0x270 ksys_write+0xab/0x120 __x64_sys_write+0x43/0x50 do_syscall_64+0x77/0x230 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f235cfe6154 Fixes: aaf45bd ("IB/srpt: Detect session shutdown reliably") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: <stable@vger.kernel.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a5ba1d9 upstream. We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 #2 [ffff88085c6db830] oops_end at ffffffff81008ae7 #3 [ffff88085c6db860] no_context at ffffffff81050b8f #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e torvalds#7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c torvalds#8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 torvalds#10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c torvalds#11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b torvalds#12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 torvalds#13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b torvalds#14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a torvalds#15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 torvalds#16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 torvalds#17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a torvalds#18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 torvalds#19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d torvalds#20 [ffff88085c6dbeb0] kthread at ffffffff81096384 torvalds#21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <tycho@tycho.ws> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3943b04 upstream. The writeback thread would exit with a lock held when the cache device is detached via sysfs interface, fix it by releasing the held lock before exiting the while-loop. Fixes: fadd94e (bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set) Signed-off-by: Shan Hai <shan.hai@oracle.com> Signed-off-by: Coly Li <colyli@suse.de> Tested-by: Shenghui Wang <shhuiw@foxmail.com> Cc: stable@vger.kernel.org #4.17+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 2093275 upstream. I changed the way mac80211 updates the PM state of the peer. I forgot that we could also have multicast frames from the peer and that those frame should of course not change the PM state of the peer: A peer goes to power save when it needs to scan, but it won't send the broadcast Probe Request with the PM bit set. This made us mark the peer as awake when it wasn't and then Intel's firmware would fail to transmit because the peer is asleep according to its database. The driver warned about this and it looked like this: WARNING: CPU: 0 PID: 184 at /usr/src/linux-4.16.14/drivers/net/wireless/intel/iwlwifi/mvm/tx.c:1369 iwl_mvm_rx_tx_cmd+0x53b/0x860 CPU: 0 PID: 184 Comm: irq/124-iwlwifi Not tainted 4.16.14 #1 RIP: 0010:iwl_mvm_rx_tx_cmd+0x53b/0x860 Call Trace: iwl_pcie_rx_handle+0x220/0x880 iwl_pcie_irq_handler+0x6c9/0xa20 ? irq_forced_thread_fn+0x60/0x60 ? irq_thread_dtor+0x90/0x90 The relevant code that spits the WARNING is: case TX_STATUS_FAIL_DEST_PS: /* the FW should have stopped the queue and not * return this status */ WARN_ON(1); info->flags |= IEEE80211_TX_STAT_TX_FILTERED; This fixes https://bugzilla.kernel.org/show_bug.cgi?id=199967. Fixes: 9fef654 ("mac80211: always update the PM state of a peer on MGMT / DATA frames") Cc: <stable@vger.kernel.org> #4.16+ Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 42bf546 ] As Wen Xu reported in below link: https://bugzilla.kernel.org/show_bug.cgi?id=200183 - Overview Divide zero in reset_curseg() when mounting a crafted f2fs image - Reproduce - Kernel message [ 588.281510] divide error: 0000 [#1] SMP KASAN PTI [ 588.282701] CPU: 0 PID: 1293 Comm: mount Not tainted 4.18.0-rc1+ #4 [ 588.284000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 588.286178] RIP: 0010:reset_curseg+0x94/0x1a0 [ 588.298166] RSP: 0018:ffff8801e88d7940 EFLAGS: 00010246 [ 588.299360] RAX: 0000000000000014 RBX: ffff8801e1d46d00 RCX: ffffffffb88bf60b [ 588.300809] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff8801e1d46d64 [ 588.305272] R13: 0000000000000000 R14: 0000000000000014 R15: 0000000000000000 [ 588.306822] FS: 00007fad85008840(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 588.308456] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 588.309623] CR2: 0000000001705078 CR3: 00000001f30f8000 CR4: 00000000000006f0 [ 588.311085] Call Trace: [ 588.311637] f2fs_build_segment_manager+0x103f/0x3410 [ 588.316136] ? f2fs_commit_super+0x1b0/0x1b0 [ 588.317031] ? set_blocksize+0x90/0x140 [ 588.319473] f2fs_mount+0x15/0x20 [ 588.320166] mount_fs+0x60/0x1a0 [ 588.320847] ? alloc_vfsmnt+0x309/0x360 [ 588.321647] vfs_kern_mount+0x6b/0x1a0 [ 588.322432] do_mount+0x34a/0x18c0 [ 588.323175] ? strndup_user+0x46/0x70 [ 588.323937] ? copy_mount_string+0x20/0x20 [ 588.324793] ? memcg_kmem_put_cache+0x1b/0xa0 [ 588.325702] ? kasan_check_write+0x14/0x20 [ 588.326562] ? _copy_from_user+0x6a/0x90 [ 588.327375] ? memdup_user+0x42/0x60 [ 588.328118] ksys_mount+0x83/0xd0 [ 588.328808] __x64_sys_mount+0x67/0x80 [ 588.329607] do_syscall_64+0x78/0x170 [ 588.330400] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 588.331461] RIP: 0033:0x7fad848e8b9a [ 588.336022] RSP: 002b:00007ffd7c5b6be8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 588.337547] RAX: ffffffffffffffda RBX: 00000000016f8030 RCX: 00007fad848e8b9a [ 588.338999] RDX: 00000000016f8210 RSI: 00000000016f9f30 RDI: 0000000001700ec0 [ 588.340442] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 588.341887] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000000001700ec0 [ 588.343341] R13: 00000000016f8210 R14: 0000000000000000 R15: 0000000000000003 [ 588.354891] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 588.355862] RIP: 0010:reset_curseg+0x94/0x1a0 [ 588.360742] RSP: 0018:ffff8801e88d7940 EFLAGS: 00010246 [ 588.361812] RAX: 0000000000000014 RBX: ffff8801e1d46d00 RCX: ffffffffb88bf60b [ 588.363485] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff8801e1d46d64 [ 588.365213] RBP: ffff8801e88d7968 R08: ffffed003c32266f R09: ffffed003c32266f [ 588.366661] R10: 0000000000000001 R11: ffffed003c32266e R12: ffff8801f0337700 [ 588.368110] R13: 0000000000000000 R14: 0000000000000014 R15: 0000000000000000 [ 588.370057] FS: 00007fad85008840(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 588.372099] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 588.373291] CR2: 0000000001705078 CR3: 00000001f30f8000 CR4: 00000000000006f0 - Location https://elixir.bootlin.com/linux/latest/source/fs/f2fs/segment.c#L2147 curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno); If secs_per_zone is corrupted due to fuzzing test, it will cause divide zero operation when using GET_ZONE_FROM_SEG macro, so we should do more sanity check with secs_per_zone during mount to avoid this issue. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit c77ec61 ] This patch adds to do sanity check with {sit,nat}_ver_bitmap_bytesize during mount, in order to avoid accessing across cache boundary with this abnormal bitmap size. - Overview buffer overrun in build_sit_info() when mounting a crafted f2fs image - Reproduce - Kernel message [ 548.580867] F2FS-fs (loop0): Invalid log blocks per segment (8201) [ 548.580877] F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock [ 548.584979] ================================================================== [ 548.586568] BUG: KASAN: use-after-free in kmemdup+0x36/0x50 [ 548.587715] Read of size 64 at addr ffff8801e9c265ff by task mount/1295 [ 548.589428] CPU: 1 PID: 1295 Comm: mount Not tainted 4.18.0-rc1+ #4 [ 548.589432] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 548.589438] Call Trace: [ 548.589474] dump_stack+0x7b/0xb5 [ 548.589487] print_address_description+0x70/0x290 [ 548.589492] kasan_report+0x291/0x390 [ 548.589496] ? kmemdup+0x36/0x50 [ 548.589509] check_memory_region+0x139/0x190 [ 548.589514] memcpy+0x23/0x50 [ 548.589518] kmemdup+0x36/0x50 [ 548.589545] f2fs_build_segment_manager+0x8fa/0x3410 [ 548.589551] ? __asan_loadN+0xf/0x20 [ 548.589560] ? f2fs_sanity_check_ckpt+0x1be/0x240 [ 548.589566] ? f2fs_flush_sit_entries+0x10c0/0x10c0 [ 548.589587] ? __put_user_ns+0x40/0x40 [ 548.589604] ? find_next_bit+0x57/0x90 [ 548.589610] f2fs_fill_super+0x194b/0x2b40 [ 548.589617] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.589637] ? set_blocksize+0x90/0x140 [ 548.589651] mount_bdev+0x1c5/0x210 [ 548.589655] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.589667] f2fs_mount+0x15/0x20 [ 548.589672] mount_fs+0x60/0x1a0 [ 548.589683] ? alloc_vfsmnt+0x309/0x360 [ 548.589688] vfs_kern_mount+0x6b/0x1a0 [ 548.589699] do_mount+0x34a/0x18c0 [ 548.589710] ? lockref_put_or_lock+0xcf/0x160 [ 548.589716] ? copy_mount_string+0x20/0x20 [ 548.589728] ? memcg_kmem_put_cache+0x1b/0xa0 [ 548.589734] ? kasan_check_write+0x14/0x20 [ 548.589740] ? _copy_from_user+0x6a/0x90 [ 548.589744] ? memdup_user+0x42/0x60 [ 548.589750] ksys_mount+0x83/0xd0 [ 548.589755] __x64_sys_mount+0x67/0x80 [ 548.589781] do_syscall_64+0x78/0x170 [ 548.589797] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 548.589820] RIP: 0033:0x7f76fc331b9a [ 548.589821] Code: 48 8b 0d 01 c3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ce c2 2b 00 f7 d8 64 89 01 48 [ 548.589880] RSP: 002b:00007ffd4f0a0e48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 548.589890] RAX: ffffffffffffffda RBX: 000000000146c030 RCX: 00007f76fc331b9a [ 548.589892] RDX: 000000000146c210 RSI: 000000000146df30 RDI: 0000000001474ec0 [ 548.589895] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 548.589897] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000000001474ec0 [ 548.589900] R13: 000000000146c210 R14: 0000000000000000 R15: 0000000000000003 [ 548.590242] The buggy address belongs to the page: [ 548.591243] page:ffffea0007a70980 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 548.592886] flags: 0x2ffff0000000000() [ 548.593665] raw: 02ffff0000000000 dead000000000100 dead000000000200 0000000000000000 [ 548.595258] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 548.603713] page dumped because: kasan: bad access detected [ 548.605203] Memory state around the buggy address: [ 548.606198] ffff8801e9c26480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.607676] ffff8801e9c26500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.609157] >ffff8801e9c26580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.610629] ^ [ 548.612088] ffff8801e9c26600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.613674] ffff8801e9c26680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 548.615141] ================================================================== [ 548.616613] Disabling lock debugging due to kernel taint [ 548.622871] WARNING: CPU: 1 PID: 1295 at mm/page_alloc.c:4065 __alloc_pages_slowpath+0xe4a/0x1420 [ 548.622878] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 548.623217] CPU: 1 PID: 1295 Comm: mount Tainted: G B 4.18.0-rc1+ #4 [ 548.623219] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 548.623226] RIP: 0010:__alloc_pages_slowpath+0xe4a/0x1420 [ 548.623227] Code: ff ff 01 89 85 c8 fe ff ff e9 91 fc ff ff 41 89 c5 e9 5c fc ff ff 0f 0b 89 f8 25 ff ff f7 ff 89 85 8c fe ff ff e9 d5 f2 ff ff <0f> 0b e9 65 f2 ff ff 65 8b 05 38 81 d2 47 f6 c4 01 74 1c 65 48 8b [ 548.623281] RSP: 0018:ffff8801f28c7678 EFLAGS: 00010246 [ 548.623284] RAX: 0000000000000000 RBX: 00000000006040c0 RCX: ffffffffb82f73b7 [ 548.623287] RDX: 1ffff1003e518eeb RSI: 000000000000000c RDI: 0000000000000000 [ 548.623290] RBP: ffff8801f28c7880 R08: 0000000000000000 R09: ffffed0047fff2c5 [ 548.623292] R10: 0000000000000001 R11: ffffed0047fff2c4 R12: ffff8801e88de040 [ 548.623295] R13: 00000000006040c0 R14: 000000000000000c R15: ffff8801f28c7938 [ 548.623299] FS: 00007f76fca51840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000 [ 548.623302] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 548.623304] CR2: 00007f19b9171760 CR3: 00000001ed952000 CR4: 00000000000006e0 [ 548.623317] Call Trace: [ 548.623325] ? kasan_check_read+0x11/0x20 [ 548.623330] ? __zone_watermark_ok+0x92/0x240 [ 548.623336] ? get_page_from_freelist+0x1c3/0x1d90 [ 548.623347] ? _raw_spin_lock_irqsave+0x2a/0x60 [ 548.623353] ? warn_alloc+0x250/0x250 [ 548.623358] ? save_stack+0x46/0xd0 [ 548.623361] ? kasan_kmalloc+0xad/0xe0 [ 548.623366] ? __isolate_free_page+0x2a0/0x2a0 [ 548.623370] ? mount_fs+0x60/0x1a0 [ 548.623374] ? vfs_kern_mount+0x6b/0x1a0 [ 548.623378] ? do_mount+0x34a/0x18c0 [ 548.623383] ? ksys_mount+0x83/0xd0 [ 548.623387] ? __x64_sys_mount+0x67/0x80 [ 548.623391] ? do_syscall_64+0x78/0x170 [ 548.623396] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 548.623401] __alloc_pages_nodemask+0x3c5/0x400 [ 548.623407] ? __alloc_pages_slowpath+0x1420/0x1420 [ 548.623412] ? __mutex_lock_slowpath+0x20/0x20 [ 548.623417] ? kvmalloc_node+0x31/0x80 [ 548.623424] alloc_pages_current+0x75/0x110 [ 548.623436] kmalloc_order+0x24/0x60 [ 548.623442] kmalloc_order_trace+0x24/0xb0 [ 548.623448] __kmalloc_track_caller+0x207/0x220 [ 548.623455] ? f2fs_build_node_manager+0x399/0xbb0 [ 548.623460] kmemdup+0x20/0x50 [ 548.623465] f2fs_build_node_manager+0x399/0xbb0 [ 548.623470] f2fs_fill_super+0x195e/0x2b40 [ 548.623477] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.623481] ? set_blocksize+0x90/0x140 [ 548.623486] mount_bdev+0x1c5/0x210 [ 548.623489] ? f2fs_commit_super+0x1b0/0x1b0 [ 548.623495] f2fs_mount+0x15/0x20 [ 548.623498] mount_fs+0x60/0x1a0 [ 548.623503] ? alloc_vfsmnt+0x309/0x360 [ 548.623508] vfs_kern_mount+0x6b/0x1a0 [ 548.623513] do_mount+0x34a/0x18c0 [ 548.623518] ? lockref_put_or_lock+0xcf/0x160 [ 548.623523] ? copy_mount_string+0x20/0x20 [ 548.623528] ? memcg_kmem_put_cache+0x1b/0xa0 [ 548.623533] ? kasan_check_write+0x14/0x20 [ 548.623537] ? _copy_from_user+0x6a/0x90 [ 548.623542] ? memdup_user+0x42/0x60 [ 548.623547] ksys_mount+0x83/0xd0 [ 548.623552] __x64_sys_mount+0x67/0x80 [ 548.623557] do_syscall_64+0x78/0x170 [ 548.623562] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 548.623566] RIP: 0033:0x7f76fc331b9a [ 548.623567] Code: 48 8b 0d 01 c3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ce c2 2b 00 f7 d8 64 89 01 48 [ 548.623632] RSP: 002b:00007ffd4f0a0e48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [ 548.623636] RAX: ffffffffffffffda RBX: 000000000146c030 RCX: 00007f76fc331b9a [ 548.623639] RDX: 000000000146c210 RSI: 000000000146df30 RDI: 0000000001474ec0 [ 548.623641] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 548.623643] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000000001474ec0 [ 548.623646] R13: 000000000146c210 R14: 0000000000000000 R15: 0000000000000003 [ 548.623650] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 548.623656] F2FS-fs (loop0): Failed to initialize F2FS node manager [ 548.627936] F2FS-fs (loop0): Invalid log blocks per segment (8201) [ 548.627940] F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock [ 548.635835] F2FS-fs (loop0): Failed to initialize F2FS node manager - Location https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/segment.c#L3578 sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL); Buffer overrun happens when doing memcpy. I suspect there is missing (inconsistent) checks on bitmap_size. Reported by Wen Xu (wen.xu@gatech.edu) from SSLab, Gatech. Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 76d56d4 ] If FI_EXTRA_ATTR is set in inode by fuzzing, inode.i_addr[0] will be parsed as inode.i_extra_isize, then in __recover_inline_status, inline data address will beyond boundary of page, result in accessing invalid memory. So in this condition, during reading inode page, let's do sanity check with EXTRA_ATTR feature of fs and extra_attr bit of inode, if they're inconsistent, deny to load this inode. - Overview Out-of-bound access in f2fs_iget() when mounting a corrupted f2fs image - Reproduce The following message will be got in KASAN build of 4.18 upstream kernel. [ 819.392227] ================================================================== [ 819.393901] BUG: KASAN: slab-out-of-bounds in f2fs_iget+0x736/0x1530 [ 819.395329] Read of size 4 at addr ffff8801f099c968 by task mount/1292 [ 819.397079] CPU: 1 PID: 1292 Comm: mount Not tainted 4.18.0-rc1+ #4 [ 819.397082] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 819.397088] Call Trace: [ 819.397124] dump_stack+0x7b/0xb5 [ 819.397154] print_address_description+0x70/0x290 [ 819.397159] kasan_report+0x291/0x390 [ 819.397163] ? f2fs_iget+0x736/0x1530 [ 819.397176] check_memory_region+0x139/0x190 [ 819.397182] __asan_loadN+0xf/0x20 [ 819.397185] f2fs_iget+0x736/0x1530 [ 819.397197] f2fs_fill_super+0x1b4f/0x2b40 [ 819.397202] ? f2fs_fill_super+0x1b4f/0x2b40 [ 819.397208] ? f2fs_commit_super+0x1b0/0x1b0 [ 819.397227] ? set_blocksize+0x90/0x140 [ 819.397241] mount_bdev+0x1c5/0x210 [ 819.397245] ? f2fs_commit_super+0x1b0/0x1b0 [ 819.397252] f2fs_mount+0x15/0x20 [ 819.397256] mount_fs+0x60/0x1a0 [ 819.397267] ? alloc_vfsmnt+0x309/0x360 [ 819.397272] vfs_kern_mount+0x6b/0x1a0 [ 819.397282] do_mount+0x34a/0x18c0 [ 819.397300] ? lockref_put_or_lock+0xcf/0x160 [ 819.397306] ? copy_mount_string+0x20/0x20 [ 819.397318] ? memcg_kmem_put_cache+0x1b/0xa0 [ 819.397324] ? kasan_check_write+0x14/0x20 [ 819.397334] ? _copy_from_user+0x6a/0x90 [ 819.397353] ? memdup_user+0x42/0x60 [ 819.397359] ksys_mount+0x83/0xd0 [ 819.397365] __x64_sys_mount+0x67/0x80 [ 819.397388] do_syscall_64+0x78/0x170 [ 819.397403] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 819.397422] RIP: 0033:0x7f54c667cb9a [ 819.397424] Code: 48 8b 0d 01 c3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ce c2 2b 00 f7 d8 64 89 01 48 [ 819.397483] RSP: 002b:00007ffd8f46cd08 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 [ 819.397496] RAX: ffffffffffffffda RBX: 0000000000dfa030 RCX: 00007f54c667cb9a [ 819.397498] RDX: 0000000000dfa210 RSI: 0000000000dfbf30 RDI: 0000000000e02ec0 [ 819.397501] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013 [ 819.397503] R10: 00000000c0ed0000 R11: 0000000000000202 R12: 0000000000e02ec0 [ 819.397505] R13: 0000000000dfa210 R14: 0000000000000000 R15: 0000000000000003 [ 819.397866] Allocated by task 139: [ 819.398702] save_stack+0x46/0xd0 [ 819.398705] kasan_kmalloc+0xad/0xe0 [ 819.398709] kasan_slab_alloc+0x11/0x20 [ 819.398713] kmem_cache_alloc+0xd1/0x1e0 [ 819.398717] dup_fd+0x50/0x4c0 [ 819.398740] copy_process.part.37+0xbed/0x32e0 [ 819.398744] _do_fork+0x16e/0x590 [ 819.398748] __x64_sys_clone+0x69/0x80 [ 819.398752] do_syscall_64+0x78/0x170 [ 819.398756] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 819.399097] Freed by task 159: [ 819.399743] save_stack+0x46/0xd0 [ 819.399747] __kasan_slab_free+0x13c/0x1a0 [ 819.399750] kasan_slab_free+0xe/0x10 [ 819.399754] kmem_cache_free+0x89/0x1e0 [ 819.399757] put_files_struct+0x132/0x150 [ 819.399761] exit_files+0x62/0x70 [ 819.399766] do_exit+0x47b/0x1390 [ 819.399770] do_group_exit+0x86/0x130 [ 819.399774] __x64_sys_exit_group+0x2c/0x30 [ 819.399778] do_syscall_64+0x78/0x170 [ 819.399782] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 819.400115] The buggy address belongs to the object at ffff8801f099c680 which belongs to the cache files_cache of size 704 [ 819.403234] The buggy address is located 40 bytes to the right of 704-byte region [ffff8801f099c680, ffff8801f099c940) [ 819.405689] The buggy address belongs to the page: [ 819.406709] page:ffffea0007c26700 count:1 mapcount:0 mapping:ffff8801f69a3340 index:0xffff8801f099d380 compound_mapcount: 0 [ 819.408984] flags: 0x2ffff0000008100(slab|head) [ 819.409932] raw: 02ffff0000008100 ffffea00077fb600 0000000200000002 ffff8801f69a3340 [ 819.411514] raw: ffff8801f099d380 0000000080130000 00000001ffffffff 0000000000000000 [ 819.413073] page dumped because: kasan: bad access detected [ 819.414539] Memory state around the buggy address: [ 819.415521] ffff8801f099c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 819.416981] ffff8801f099c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 819.418454] >ffff8801f099c900: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 819.419921] ^ [ 819.421265] ffff8801f099c980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 819.422745] ffff8801f099ca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 819.424206] ================================================================== [ 819.425668] Disabling lock debugging due to kernel taint [ 819.457463] F2FS-fs (loop0): Mounted with checkpoint version = 3 The kernel still mounts the image. If you run the following program on the mounted folder mnt, (poc.c) static void activity(char *mpoint) { char *foo_bar_baz; int err; static int buf[8192]; memset(buf, 0, sizeof(buf)); err = asprintf(&foo_bar_baz, "%s/foo/bar/baz", mpoint); int fd = open(foo_bar_baz, O_RDONLY, 0); if (fd >= 0) { read(fd, (char *)buf, 11); close(fd); } } int main(int argc, char *argv[]) { activity(argv[1]); return 0; } You can get kernel crash: [ 819.457463] F2FS-fs (loop0): Mounted with checkpoint version = 3 [ 918.028501] BUG: unable to handle kernel paging request at ffffed0048000d82 [ 918.044020] PGD 23ffee067 P4D 23ffee067 PUD 23fbef067 PMD 0 [ 918.045207] Oops: 0000 [#1] SMP KASAN PTI [ 918.046048] CPU: 0 PID: 1309 Comm: poc Tainted: G B 4.18.0-rc1+ #4 [ 918.047573] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 918.049552] RIP: 0010:check_memory_region+0x5e/0x190 [ 918.050565] Code: f8 49 c1 e8 03 49 89 db 49 c1 eb 03 4d 01 cb 4d 01 c1 4d 8d 63 01 4c 89 c8 4d 89 e2 4d 29 ca 49 83 fa 10 7f 3d 4d 85 d2 74 32 <41> 80 39 00 75 23 48 b8 01 00 00 00 00 fc ff df 4d 01 d1 49 01 c0 [ 918.054322] RSP: 0018:ffff8801e3a1f258 EFLAGS: 00010202 [ 918.055400] RAX: ffffed0048000d82 RBX: ffff880240006c11 RCX: ffffffffb8867d14 [ 918.056832] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff880240006c10 [ 918.058253] RBP: ffff8801e3a1f268 R08: 1ffff10048000d82 R09: ffffed0048000d82 [ 918.059717] R10: 0000000000000001 R11: ffffed0048000d82 R12: ffffed0048000d83 [ 918.061159] R13: ffff8801e3a1f390 R14: 0000000000000000 R15: ffff880240006c08 [ 918.062614] FS: 00007fac9732c700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 918.064246] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 918.065412] CR2: ffffed0048000d82 CR3: 00000001df77a000 CR4: 00000000000006f0 [ 918.066882] Call Trace: [ 918.067410] __asan_loadN+0xf/0x20 [ 918.068149] f2fs_find_target_dentry+0xf4/0x270 [ 918.069083] ? __get_node_page+0x331/0x5b0 [ 918.069925] f2fs_find_in_inline_dir+0x24b/0x310 [ 918.070881] ? f2fs_recover_inline_data+0x4c0/0x4c0 [ 918.071905] ? unwind_next_frame.part.5+0x34f/0x490 [ 918.072901] ? unwind_dump+0x290/0x290 [ 918.073695] ? is_bpf_text_address+0xe/0x20 [ 918.074566] __f2fs_find_entry+0x599/0x670 [ 918.075408] ? kasan_unpoison_shadow+0x36/0x50 [ 918.076315] ? kasan_kmalloc+0xad/0xe0 [ 918.077100] ? memcg_kmem_put_cache+0x55/0xa0 [ 918.077998] ? f2fs_find_target_dentry+0x270/0x270 [ 918.079006] ? d_set_d_op+0x30/0x100 [ 918.079749] ? __d_lookup_rcu+0x69/0x2e0 [ 918.080556] ? __d_alloc+0x275/0x450 [ 918.081297] ? kasan_check_write+0x14/0x20 [ 918.082135] ? memset+0x31/0x40 [ 918.082820] ? fscrypt_setup_filename+0x1ec/0x4c0 [ 918.083782] ? d_alloc_parallel+0x5bb/0x8c0 [ 918.084640] f2fs_find_entry+0xe9/0x110 [ 918.085432] ? __f2fs_find_entry+0x670/0x670 [ 918.086308] ? kasan_check_write+0x14/0x20 [ 918.087163] f2fs_lookup+0x297/0x590 [ 918.087902] ? f2fs_link+0x2b0/0x2b0 [ 918.088646] ? legitimize_path.isra.29+0x61/0xa0 [ 918.089589] __lookup_slow+0x12e/0x240 [ 918.090371] ? may_delete+0x2b0/0x2b0 [ 918.091123] ? __nd_alloc_stack+0xa0/0xa0 [ 918.091944] lookup_slow+0x44/0x60 [ 918.092642] walk_component+0x3ee/0xa40 [ 918.093428] ? is_bpf_text_address+0xe/0x20 [ 918.094283] ? pick_link+0x3e0/0x3e0 [ 918.095047] ? in_group_p+0xa5/0xe0 [ 918.095771] ? generic_permission+0x53/0x1e0 [ 918.096666] ? security_inode_permission+0x1d/0x70 [ 918.097646] ? inode_permission+0x7a/0x1f0 [ 918.098497] link_path_walk+0x2a2/0x7b0 [ 918.099298] ? apparmor_capget+0x3d0/0x3d0 [ 918.100140] ? walk_component+0xa40/0xa40 [ 918.100958] ? path_init+0x2e6/0x580 [ 918.101695] path_openat+0x1bb/0x2160 [ 918.102471] ? __save_stack_trace+0x92/0x100 [ 918.103352] ? save_stack+0xb5/0xd0 [ 918.104070] ? vfs_unlink+0x250/0x250 [ 918.104822] ? save_stack+0x46/0xd0 [ 918.105538] ? kasan_slab_alloc+0x11/0x20 [ 918.106370] ? kmem_cache_alloc+0xd1/0x1e0 [ 918.107213] ? getname_flags+0x76/0x2c0 [ 918.107997] ? getname+0x12/0x20 [ 918.108677] ? do_sys_open+0x14b/0x2c0 [ 918.109450] ? __x64_sys_open+0x4c/0x60 [ 918.110255] ? do_syscall_64+0x78/0x170 [ 918.111083] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 918.112148] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 918.113204] ? f2fs_empty_inline_dir+0x1e0/0x1e0 [ 918.114150] ? timespec64_trunc+0x5c/0x90 [ 918.114993] ? wb_io_lists_depopulated+0x1a/0xc0 [ 918.115937] ? inode_io_list_move_locked+0x102/0x110 [ 918.116949] do_filp_open+0x12b/0x1d0 [ 918.117709] ? may_open_dev+0x50/0x50 [ 918.118475] ? kasan_kmalloc+0xad/0xe0 [ 918.119246] do_sys_open+0x17c/0x2c0 [ 918.119983] ? do_sys_open+0x17c/0x2c0 [ 918.120751] ? filp_open+0x60/0x60 [ 918.121463] ? task_work_run+0x4d/0xf0 [ 918.122237] __x64_sys_open+0x4c/0x60 [ 918.123001] do_syscall_64+0x78/0x170 [ 918.123759] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 918.124802] RIP: 0033:0x7fac96e3e040 [ 918.125537] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 09 27 2d 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 7e e0 01 00 48 89 04 24 [ 918.129341] RSP: 002b:00007fff1b37f848 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 918.130870] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fac96e3e040 [ 918.132295] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000122d080 [ 918.133748] RBP: 00007fff1b37f9b0 R08: 00007fac9710bbd8 R09: 0000000000000001 [ 918.135209] R10: 000000000000069d R11: 0000000000000246 R12: 0000000000400c20 [ 918.136650] R13: 00007fff1b37fab0 R14: 0000000000000000 R15: 0000000000000000 [ 918.138093] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy [ 918.147924] CR2: ffffed0048000d82 [ 918.148619] ---[ end trace 4ce02f25ff7d3df5 ]--- [ 918.149563] RIP: 0010:check_memory_region+0x5e/0x190 [ 918.150576] Code: f8 49 c1 e8 03 49 89 db 49 c1 eb 03 4d 01 cb 4d 01 c1 4d 8d 63 01 4c 89 c8 4d 89 e2 4d 29 ca 49 83 fa 10 7f 3d 4d 85 d2 74 32 <41> 80 39 00 75 23 48 b8 01 00 00 00 00 fc ff df 4d 01 d1 49 01 c0 [ 918.154360] RSP: 0018:ffff8801e3a1f258 EFLAGS: 00010202 [ 918.155411] RAX: ffffed0048000d82 RBX: ffff880240006c11 RCX: ffffffffb8867d14 [ 918.156833] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff880240006c10 [ 918.158257] RBP: ffff8801e3a1f268 R08: 1ffff10048000d82 R09: ffffed0048000d82 [ 918.159722] R10: 0000000000000001 R11: ffffed0048000d82 R12: ffffed0048000d83 [ 918.161149] R13: ffff8801e3a1f390 R14: 0000000000000000 R15: ffff880240006c08 [ 918.162587] FS: 00007fac9732c700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000 [ 918.164203] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 918.165356] CR2: ffffed0048000d82 CR3: 00000001df77a000 CR4: 00000000000006f0 Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 46b3722 ] We occasionaly hit following assert failure in 'perf top', when processing the /proc info in multiple threads. perf: ...include/linux/refcount.h:109: refcount_inc: Assertion `!(!refcount_inc_not_zero(r))' failed. The gdb backtrace looks like this: [Switching to Thread 0x7ffff11ba700 (LWP 13749)] 0x00007ffff50839fb in raise () from /lib64/libc.so.6 (gdb) #0 0x00007ffff50839fb in raise () from /lib64/libc.so.6 #1 0x00007ffff5085800 in abort () from /lib64/libc.so.6 #2 0x00007ffff507c0da in __assert_fail_base () from /lib64/libc.so.6 #3 0x00007ffff507c152 in __assert_fail () from /lib64/libc.so.6 #4 0x0000000000535373 in refcount_inc (r=0x7fffdc009be0) at ...include/linux/refcount.h:109 #5 0x00000000005354f1 in comm_str__get (cs=0x7fffdc009bc0) at util/comm.c:24 #6 0x00000000005356bd in __comm_str__findnew (str=0x7fffd000b260 ":2", root=0xbed5c0 <comm_str_root>) at util/comm.c:72 torvalds#7 0x000000000053579e in comm_str__findnew (str=0x7fffd000b260 ":2", root=0xbed5c0 <comm_str_root>) at util/comm.c:95 torvalds#8 0x000000000053582e in comm__new (str=0x7fffd000b260 ":2", timestamp=0, exec=false) at util/comm.c:111 torvalds#9 0x00000000005363bc in thread__new (pid=2, tid=2) at util/thread.c:57 torvalds#10 0x0000000000523da0 in ____machine__findnew_thread (machine=0xbfde38, threads=0xbfdf28, pid=2, tid=2, create=true) at util/machine.c:457 torvalds#11 0x0000000000523eb4 in __machine__findnew_thread (machine=0xbfde38, ... The failing assertion is this one: REFCOUNT_WARN(!refcount_inc_not_zero(r), ... The problem is that we keep global comm_str_root list, which is accessed by multiple threads during the 'perf top' startup and following 2 paths can race: thread 1: ... thread__new comm__new comm_str__findnew down_write(&comm_str_lock); __comm_str__findnew comm_str__get thread 2: ... comm__override or comm__free comm_str__put refcount_dec_and_test down_write(&comm_str_lock); rb_erase(&cs->rb_node, &comm_str_root); Because thread 2 first decrements the refcnt and only after then it removes the struct comm_str from the list, the thread 1 can find this object on the list with refcnt equls to 0 and hit the assert. This patch fixes the thread 1 __comm_str__findnew path, by ignoring objects that already dropped the refcnt to 0. For the rest of the objects we take the refcnt before comparing its name and release it afterwards with comm_str__put, which can also release the object completely. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Lukasz Odzioba <lukasz.odzioba@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20180720101740.GA27176@krava Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8edfe2e upstream. Commit 822fb18 ("xen-netfront: wait xenbus state change when load module manually") added a new wait queue to wait on for a state change when the module is loaded manually. Unfortunately there is no wakeup anywhere to stop that waiting. Instead of introducing a new wait queue rename the existing module_unload_q to module_wq and use it for both purposes (loading and unloading). As any state change of the backend might be intended to stop waiting do the wake_up_all() in any case when netback_changed() is called. Fixes: 822fb18 ("xen-netfront: wait xenbus state change when load module manually") Cc: <stable@vger.kernel.org> #4.18 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit b71c69c ] Fixes this warning that was provoked by a pairing: [60258.016221] WARNING: possible recursive locking detected [60258.021558] 4.15.0-RD1812-BSP #1 Tainted: G O [60258.027146] -------------------------------------------- [60258.032464] kworker/u5:0/70 is trying to acquire lock: [60258.037609] (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}, at: [<87759073>] bt_accept_enqueue+0x3c/0x74 [60258.046863] [60258.046863] but task is already holding lock: [60258.052704] (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}, at: [<d22d7106>] l2cap_sock_new_connection_cb+0x1c/0x88 [60258.062905] [60258.062905] other info that might help us debug this: [60258.069441] Possible unsafe locking scenario: [60258.069441] [60258.075368] CPU0 [60258.077821] ---- [60258.080272] lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); [60258.085510] lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); [60258.090748] [60258.090748] *** DEADLOCK *** [60258.090748] [60258.096676] May be due to missing lock nesting notation [60258.096676] [60258.103472] 5 locks held by kworker/u5:0/70: [60258.107747] #0: ((wq_completion)%shdev->name#2){+.+.}, at: [<9460d092>] process_one_work+0x130/0x4fc [60258.117263] #1: ((work_completion)(&hdev->rx_work)){+.+.}, at: [<9460d092>] process_one_work+0x130/0x4fc [60258.126942] #2: (&conn->chan_lock){+.+.}, at: [<7877c8c3>] l2cap_connect+0x80/0x4f8 [60258.134806] #3: (&chan->lock/2){+.+.}, at: [<2e16c724>] l2cap_connect+0x8c/0x4f8 [60258.142410] #4: (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}, at: [<d22d7106>] l2cap_sock_new_connection_cb+0x1c/0x88 [60258.153043] [60258.153043] stack backtrace: [60258.157413] CPU: 1 PID: 70 Comm: kworker/u5:0 Tainted: G O 4.15.0-RD1812-BSP #1 [60258.165945] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [60258.172485] Workqueue: hci0 hci_rx_work [60258.176331] Backtrace: [60258.178797] [<8010c9fc>] (dump_backtrace) from [<8010ccbc>] (show_stack+0x18/0x1c) [60258.186379] r7:80e55fe4 r6:80e55fe4 r5:20050093 r4:00000000 [60258.192058] [<8010cca4>] (show_stack) from [<809864e8>] (dump_stack+0xb0/0xdc) [60258.199301] [<80986438>] (dump_stack) from [<8016ecc8>] (__lock_acquire+0xffc/0x11d4) [60258.207144] r9:5e2bb019 r8:630f974c r7:ba8a5940 r6:ba8a5ed8 r5:815b5220 r4:80fa081c [60258.214901] [<8016dccc>] (__lock_acquire) from [<8016f620>] (lock_acquire+0x78/0x98) [60258.222655] r10:00000040 r9:00000040 r8:808729f0 r7:00000001 r6:00000000 r5:60050013 [60258.230491] r4:00000000 [60258.233045] [<8016f5a8>] (lock_acquire) from [<806ee974>] (lock_sock_nested+0x64/0x88) [60258.240970] r7:00000000 r6:b796e870 r5:00000001 r4:b796e800 [60258.246643] [<806ee910>] (lock_sock_nested) from [<808729f0>] (bt_accept_enqueue+0x3c/0x74) [60258.255004] r8:00000001 r7:ba7d3c00 r6:ba7d3ea4 r5:ba7d2000 r4:b796e800 [60258.261717] [<808729b4>] (bt_accept_enqueue) from [<808aa39c>] (l2cap_sock_new_connection_cb+0x68/0x88) [60258.271117] r5:b796e800 r4:ba7d2000 [60258.274708] [<808aa334>] (l2cap_sock_new_connection_cb) from [<808a294c>] (l2cap_connect+0x190/0x4f8) [60258.283933] r5:00000001 r4:ba6dce00 [60258.287524] [<808a27bc>] (l2cap_connect) from [<808a4a14>] (l2cap_recv_frame+0x744/0x2cf8) [60258.295800] r10:ba6dcf24 r9:00000004 r8:b78d8014 r7:00000004 r6:bb05d000 r5:00000004 [60258.303635] r4:bb05d008 [60258.306183] [<808a42d0>] (l2cap_recv_frame) from [<808a7808>] (l2cap_recv_acldata+0x210/0x214) [60258.314805] r10:b78e7800 r9:bb05d960 r8:00000001 r7:bb05d000 r6:0000000c r5:b7957a80 [60258.322641] r4:ba6dce00 [60258.325188] [<808a75f8>] (l2cap_recv_acldata) from [<8087630c>] (hci_rx_work+0x35c/0x4e8) [60258.333374] r6:80e5743c r5:bb05d7c8 r4:b7957a80 [60258.338004] [<80875fb0>] (hci_rx_work) from [<8013dc7c>] (process_one_work+0x1a4/0x4fc) [60258.346018] r10:00000001 r9:00000000 r8:baabfef8 r7:ba997500 r6:baaba800 r5:baaa5d00 [60258.353853] r4:bb05d7c8 [60258.356401] [<8013dad8>] (process_one_work) from [<8013e028>] (worker_thread+0x54/0x5cc) [60258.364503] r10:baabe038 r9:baaba834 r8:80e05900 r7:00000088 r6:baaa5d18 r5:baaba800 [60258.372338] r4:baaa5d00 [60258.374888] [<8013dfd4>] (worker_thread) from [<801448f8>] (kthread+0x134/0x160) [60258.382295] r10:ba8310b8 r9:bb07dbfc r8:8013dfd4 r7:baaa5d00 r6:00000000 r5:baaa8ac0 [60258.390130] r4:ba831080 [60258.392682] [<801447c4>] (kthread) from [<801080b4>] (ret_from_fork+0x14/0x20) [60258.399915] r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:801447c4 [60258.407751] r4:baaa8ac0 r3:baabe000 Signed-off-by: Philipp Puschmann <pp@emlix.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 018349d ] When netvsc device is removed it can call reschedule in RCU context. This happens because canceling the subchannel setup work could (in theory) cause a reschedule when manipulating the timer. To reproduce, run with lockdep enabled kernel and unbind a network device from hv_netvsc (via sysfs). [ 160.682011] WARNING: suspicious RCU usage [ 160.707466] 4.19.0-rc3-uio+ #2 Not tainted [ 160.709937] ----------------------------- [ 160.712352] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section! [ 160.723691] [ 160.723691] other info that might help us debug this: [ 160.723691] [ 160.730955] [ 160.730955] rcu_scheduler_active = 2, debug_locks = 1 [ 160.762813] 5 locks held by rebind-eth.sh/1812: [ 160.766851] #0: 000000008befa37a (sb_writers#6){.+.+}, at: vfs_write+0x184/0x1b0 [ 160.773416] #1: 00000000b097f236 (&of->mutex){+.+.}, at: kernfs_fop_write+0xe2/0x1a0 [ 160.783766] #2: 0000000041ee6889 (kn->count#3){++++}, at: kernfs_fop_write+0xeb/0x1a0 [ 160.787465] #3: 0000000056d92a74 (&dev->mutex){....}, at: device_release_driver_internal+0x39/0x250 [ 160.816987] #4: 0000000030f6031e (rcu_read_lock){....}, at: netvsc_remove+0x1e/0x250 [hv_netvsc] [ 160.828629] [ 160.828629] stack backtrace: [ 160.831966] CPU: 1 PID: 1812 Comm: rebind-eth.sh Not tainted 4.19.0-rc3-uio+ #2 [ 160.832952] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 [ 160.832952] Call Trace: [ 160.832952] dump_stack+0x85/0xcb [ 160.832952] ___might_sleep+0x1a3/0x240 [ 160.832952] __flush_work+0x57/0x2e0 [ 160.832952] ? __mutex_lock+0x83/0x990 [ 160.832952] ? __kernfs_remove+0x24f/0x2e0 [ 160.832952] ? __kernfs_remove+0x1b2/0x2e0 [ 160.832952] ? mark_held_locks+0x50/0x80 [ 160.832952] ? get_work_pool+0x90/0x90 [ 160.832952] __cancel_work_timer+0x13c/0x1e0 [ 160.832952] ? netvsc_remove+0x1e/0x250 [hv_netvsc] [ 160.832952] ? __lock_is_held+0x55/0x90 [ 160.832952] netvsc_remove+0x9a/0x250 [hv_netvsc] [ 160.832952] vmbus_remove+0x26/0x30 [ 160.832952] device_release_driver_internal+0x18a/0x250 [ 160.832952] unbind_store+0xb4/0x180 [ 160.832952] kernfs_fop_write+0x113/0x1a0 [ 160.832952] __vfs_write+0x36/0x1a0 [ 160.832952] ? rcu_read_lock_sched_held+0x6b/0x80 [ 160.832952] ? rcu_sync_lockdep_assert+0x2e/0x60 [ 160.832952] ? __sb_start_write+0x141/0x1a0 [ 160.832952] ? vfs_write+0x184/0x1b0 [ 160.832952] vfs_write+0xbe/0x1b0 [ 160.832952] ksys_write+0x55/0xc0 [ 160.832952] do_syscall_64+0x60/0x1b0 [ 160.832952] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 160.832952] RIP: 0033:0x7fe48f4c8154 Resolve this by getting RTNL earlier. This is safe because the subchannel work queue does trylock on RTNL and will detect the race. Fixes: 7b2ee50 ("hv_netvsc: common detach logic") Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3e1a127 upstream. When we disable hotplugging on the GPU, we need to be able to synchronize with each connector's hotplug interrupt handler before the interrupt is finally disabled. This can be a problem however, since nouveau_connector_detect() currently grabs a runtime power reference when handling connector probing. This will deadlock the runtime suspend handler like so: [ 861.480896] INFO: task kworker/0:2:61 blocked for more than 120 seconds. [ 861.483290] Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.485158] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.486332] kworker/0:2 D 0 61 2 0x80000000 [ 861.487044] Workqueue: events nouveau_display_hpd_work [nouveau] [ 861.487737] Call Trace: [ 861.488394] __schedule+0x322/0xaf0 [ 861.489070] schedule+0x33/0x90 [ 861.489744] rpm_resume+0x19c/0x850 [ 861.490392] ? finish_wait+0x90/0x90 [ 861.491068] __pm_runtime_resume+0x4e/0x90 [ 861.491753] nouveau_display_hpd_work+0x22/0x60 [nouveau] [ 861.492416] process_one_work+0x231/0x620 [ 861.493068] worker_thread+0x44/0x3a0 [ 861.493722] kthread+0x12b/0x150 [ 861.494342] ? wq_pool_ids_show+0x140/0x140 [ 861.494991] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.495648] ret_from_fork+0x3a/0x50 [ 861.496304] INFO: task kworker/6:2:320 blocked for more than 120 seconds. [ 861.496968] Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.497654] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.498341] kworker/6:2 D 0 320 2 0x80000080 [ 861.499045] Workqueue: pm pm_runtime_work [ 861.499739] Call Trace: [ 861.500428] __schedule+0x322/0xaf0 [ 861.501134] ? wait_for_completion+0x104/0x190 [ 861.501851] schedule+0x33/0x90 [ 861.502564] schedule_timeout+0x3a5/0x590 [ 861.503284] ? mark_held_locks+0x58/0x80 [ 861.503988] ? _raw_spin_unlock_irq+0x2c/0x40 [ 861.504710] ? wait_for_completion+0x104/0x190 [ 861.505417] ? trace_hardirqs_on_caller+0xf4/0x190 [ 861.506136] ? wait_for_completion+0x104/0x190 [ 861.506845] wait_for_completion+0x12c/0x190 [ 861.507555] ? wake_up_q+0x80/0x80 [ 861.508268] flush_work+0x1c9/0x280 [ 861.508990] ? flush_workqueue_prep_pwqs+0x1b0/0x1b0 [ 861.509735] nvif_notify_put+0xb1/0xc0 [nouveau] [ 861.510482] nouveau_display_fini+0xbd/0x170 [nouveau] [ 861.511241] nouveau_display_suspend+0x67/0x120 [nouveau] [ 861.511969] nouveau_do_suspend+0x5e/0x2d0 [nouveau] [ 861.512715] nouveau_pmops_runtime_suspend+0x47/0xb0 [nouveau] [ 861.513435] pci_pm_runtime_suspend+0x6b/0x180 [ 861.514165] ? pci_has_legacy_pm_support+0x70/0x70 [ 861.514897] __rpm_callback+0x7a/0x1d0 [ 861.515618] ? pci_has_legacy_pm_support+0x70/0x70 [ 861.516313] rpm_callback+0x24/0x80 [ 861.517027] ? pci_has_legacy_pm_support+0x70/0x70 [ 861.517741] rpm_suspend+0x142/0x6b0 [ 861.518449] pm_runtime_work+0x97/0xc0 [ 861.519144] process_one_work+0x231/0x620 [ 861.519831] worker_thread+0x44/0x3a0 [ 861.520522] kthread+0x12b/0x150 [ 861.521220] ? wq_pool_ids_show+0x140/0x140 [ 861.521925] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.522622] ret_from_fork+0x3a/0x50 [ 861.523299] INFO: task kworker/6:0:1329 blocked for more than 120 seconds. [ 861.523977] Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.524644] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.525349] kworker/6:0 D 0 1329 2 0x80000000 [ 861.526073] Workqueue: events nvif_notify_work [nouveau] [ 861.526751] Call Trace: [ 861.527411] __schedule+0x322/0xaf0 [ 861.528089] schedule+0x33/0x90 [ 861.528758] rpm_resume+0x19c/0x850 [ 861.529399] ? finish_wait+0x90/0x90 [ 861.530073] __pm_runtime_resume+0x4e/0x90 [ 861.530798] nouveau_connector_detect+0x7e/0x510 [nouveau] [ 861.531459] ? ww_mutex_lock+0x47/0x80 [ 861.532097] ? ww_mutex_lock+0x47/0x80 [ 861.532819] ? drm_modeset_lock+0x88/0x130 [drm] [ 861.533481] drm_helper_probe_detect_ctx+0xa0/0x100 [drm_kms_helper] [ 861.534127] drm_helper_hpd_irq_event+0xa4/0x120 [drm_kms_helper] [ 861.534940] nouveau_connector_hotplug+0x98/0x120 [nouveau] [ 861.535556] nvif_notify_work+0x2d/0xb0 [nouveau] [ 861.536221] process_one_work+0x231/0x620 [ 861.536994] worker_thread+0x44/0x3a0 [ 861.537757] kthread+0x12b/0x150 [ 861.538463] ? wq_pool_ids_show+0x140/0x140 [ 861.539102] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.539815] ret_from_fork+0x3a/0x50 [ 861.540521] Showing all locks held in the system: [ 861.541696] 2 locks held by kworker/0:2/61: [ 861.542406] #0: 000000002dbf8af5 ((wq_completion)"events"){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.543071] #1: 0000000076868126 ((work_completion)(&drm->hpd_work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.543814] 1 lock held by khungtaskd/64: [ 861.544535] #0: 0000000059db4b53 (rcu_read_lock){....}, at: debug_show_all_locks+0x23/0x185 [ 861.545160] 3 locks held by kworker/6:2/320: [ 861.545896] #0: 00000000d9e1bc59 ((wq_completion)"pm"){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.546702] #1: 00000000c9f92d84 ((work_completion)(&dev->power.work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.547443] #2: 000000004afc5de1 (drm_connector_list_iter){.+.+}, at: nouveau_display_fini+0x96/0x170 [nouveau] [ 861.548146] 1 lock held by dmesg/983: [ 861.548889] 2 locks held by zsh/1250: [ 861.549605] #0: 00000000348e3cf6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.550393] #1: 000000007009a7a8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0xc1/0x870 [ 861.551122] 6 locks held by kworker/6:0/1329: [ 861.551957] #0: 000000002dbf8af5 ((wq_completion)"events"){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.552765] #1: 00000000ddb499ad ((work_completion)(&notify->work)#2){+.+.}, at: process_one_work+0x1b3/0x620 [ 861.553582] #2: 000000006e013cbe (&dev->mode_config.mutex){+.+.}, at: drm_helper_hpd_irq_event+0x6c/0x120 [drm_kms_helper] [ 861.554357] #3: 000000004afc5de1 (drm_connector_list_iter){.+.+}, at: drm_helper_hpd_irq_event+0x78/0x120 [drm_kms_helper] [ 861.555227] #4: 0000000044f294d9 (crtc_ww_class_acquire){+.+.}, at: drm_helper_probe_detect_ctx+0x3d/0x100 [drm_kms_helper] [ 861.556133] #5: 00000000db193642 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_lock+0x4b/0x130 [drm] [ 861.557864] ============================================= [ 861.559507] NMI backtrace for cpu 2 [ 861.560363] CPU: 2 PID: 64 Comm: khungtaskd Tainted: G O 4.18.0-rc6Lyude-Test+ #1 [ 861.561197] Hardware name: LENOVO 20EQS64N0B/20EQS64N0B, BIOS N1EET78W (1.51 ) 05/18/2018 [ 861.561948] Call Trace: [ 861.562757] dump_stack+0x8e/0xd3 [ 861.563516] nmi_cpu_backtrace.cold.3+0x14/0x5a [ 861.564269] ? lapic_can_unplug_cpu.cold.27+0x42/0x42 [ 861.565029] nmi_trigger_cpumask_backtrace+0xa1/0xae [ 861.565789] arch_trigger_cpumask_backtrace+0x19/0x20 [ 861.566558] watchdog+0x316/0x580 [ 861.567355] kthread+0x12b/0x150 [ 861.568114] ? reset_hung_task_detector+0x20/0x20 [ 861.568863] ? kthread_create_worker_on_cpu+0x70/0x70 [ 861.569598] ret_from_fork+0x3a/0x50 [ 861.570370] Sending NMI from CPU 2 to CPUs 0-1,3-7: [ 861.571426] NMI backtrace for cpu 6 skipped: idling at intel_idle+0x7f/0x120 [ 861.571429] NMI backtrace for cpu 7 skipped: idling at intel_idle+0x7f/0x120 [ 861.571432] NMI backtrace for cpu 3 skipped: idling at intel_idle+0x7f/0x120 [ 861.571464] NMI backtrace for cpu 5 skipped: idling at intel_idle+0x7f/0x120 [ 861.571467] NMI backtrace for cpu 0 skipped: idling at intel_idle+0x7f/0x120 [ 861.571469] NMI backtrace for cpu 4 skipped: idling at intel_idle+0x7f/0x120 [ 861.571472] NMI backtrace for cpu 1 skipped: idling at intel_idle+0x7f/0x120 [ 861.572428] Kernel panic - not syncing: hung_task: blocked tasks So: fix this by making it so that normal hotplug handling /only/ happens so long as the GPU is currently awake without any pending runtime PM requests. In the event that a hotplug occurs while the device is suspending or resuming, we can simply defer our response until the GPU is fully runtime resumed again. Changes since v4: - Use a new trick I came up with using pm_runtime_get() instead of the hackish junk we had before Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Karol Herbst <kherbst@redhat.com> Acked-by: Daniel Vetter <daniel@ffwll.ch> Cc: stable@vger.kernel.org Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ben Skeggs <bskeggs@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

…equests commit 7fec8f5 upstream. Currently, nouveau uses the generic drm_fb_helper_output_poll_changed() function provided by DRM as it's output_poll_changed callback. Unfortunately however, this function doesn't grab runtime PM references early enough and even if it did-we can't block waiting for the device to resume in output_poll_changed() since it's very likely that we'll need to grab the fb_helper lock at some point during the runtime resume process. This currently results in deadlocking like so: [ 246.669625] INFO: task kworker/4:0:37 blocked for more than 120 seconds. [ 246.673398] Not tainted 4.18.0-rc5Lyude-Test+ #2 [ 246.675271] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 246.676527] kworker/4:0 D 0 37 2 0x80000000 [ 246.677580] Workqueue: events output_poll_execute [drm_kms_helper] [ 246.678704] Call Trace: [ 246.679753] __schedule+0x322/0xaf0 [ 246.680916] schedule+0x33/0x90 [ 246.681924] schedule_preempt_disabled+0x15/0x20 [ 246.683023] __mutex_lock+0x569/0x9a0 [ 246.684035] ? kobject_uevent_env+0x117/0x7b0 [ 246.685132] ? drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.686179] mutex_lock_nested+0x1b/0x20 [ 246.687278] ? mutex_lock_nested+0x1b/0x20 [ 246.688307] drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.689420] drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper] [ 246.690462] drm_kms_helper_hotplug_event+0x2a/0x30 [drm_kms_helper] [ 246.691570] output_poll_execute+0x198/0x1c0 [drm_kms_helper] [ 246.692611] process_one_work+0x231/0x620 [ 246.693725] worker_thread+0x214/0x3a0 [ 246.694756] kthread+0x12b/0x150 [ 246.695856] ? wq_pool_ids_show+0x140/0x140 [ 246.696888] ? kthread_create_worker_on_cpu+0x70/0x70 [ 246.697998] ret_from_fork+0x3a/0x50 [ 246.699034] INFO: task kworker/0:1:60 blocked for more than 120 seconds. [ 246.700153] Not tainted 4.18.0-rc5Lyude-Test+ #2 [ 246.701182] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 246.702278] kworker/0:1 D 0 60 2 0x80000000 [ 246.703293] Workqueue: pm pm_runtime_work [ 246.704393] Call Trace: [ 246.705403] __schedule+0x322/0xaf0 [ 246.706439] ? wait_for_completion+0x104/0x190 [ 246.707393] schedule+0x33/0x90 [ 246.708375] schedule_timeout+0x3a5/0x590 [ 246.709289] ? mark_held_locks+0x58/0x80 [ 246.710208] ? _raw_spin_unlock_irq+0x2c/0x40 [ 246.711222] ? wait_for_completion+0x104/0x190 [ 246.712134] ? trace_hardirqs_on_caller+0xf4/0x190 [ 246.713094] ? wait_for_completion+0x104/0x190 [ 246.713964] wait_for_completion+0x12c/0x190 [ 246.714895] ? wake_up_q+0x80/0x80 [ 246.715727] ? get_work_pool+0x90/0x90 [ 246.716649] flush_work+0x1c9/0x280 [ 246.717483] ? flush_workqueue_prep_pwqs+0x1b0/0x1b0 [ 246.718442] __cancel_work_timer+0x146/0x1d0 [ 246.719247] cancel_delayed_work_sync+0x13/0x20 [ 246.720043] drm_kms_helper_poll_disable+0x1f/0x30 [drm_kms_helper] [ 246.721123] nouveau_pmops_runtime_suspend+0x3d/0xb0 [nouveau] [ 246.721897] pci_pm_runtime_suspend+0x6b/0x190 [ 246.722825] ? pci_has_legacy_pm_support+0x70/0x70 [ 246.723737] __rpm_callback+0x7a/0x1d0 [ 246.724721] ? pci_has_legacy_pm_support+0x70/0x70 [ 246.725607] rpm_callback+0x24/0x80 [ 246.726553] ? pci_has_legacy_pm_support+0x70/0x70 [ 246.727376] rpm_suspend+0x142/0x6b0 [ 246.728185] pm_runtime_work+0x97/0xc0 [ 246.728938] process_one_work+0x231/0x620 [ 246.729796] worker_thread+0x44/0x3a0 [ 246.730614] kthread+0x12b/0x150 [ 246.731395] ? wq_pool_ids_show+0x140/0x140 [ 246.732202] ? kthread_create_worker_on_cpu+0x70/0x70 [ 246.732878] ret_from_fork+0x3a/0x50 [ 246.733768] INFO: task kworker/4:2:422 blocked for more than 120 seconds. [ 246.734587] Not tainted 4.18.0-rc5Lyude-Test+ #2 [ 246.735393] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 246.736113] kworker/4:2 D 0 422 2 0x80000080 [ 246.736789] Workqueue: events_long drm_dp_mst_link_probe_work [drm_kms_helper] [ 246.737665] Call Trace: [ 246.738490] __schedule+0x322/0xaf0 [ 246.739250] schedule+0x33/0x90 [ 246.739908] rpm_resume+0x19c/0x850 [ 246.740750] ? finish_wait+0x90/0x90 [ 246.741541] __pm_runtime_resume+0x4e/0x90 [ 246.742370] nv50_disp_atomic_commit+0x31/0x210 [nouveau] [ 246.743124] drm_atomic_commit+0x4a/0x50 [drm] [ 246.743775] restore_fbdev_mode_atomic+0x1c8/0x240 [drm_kms_helper] [ 246.744603] restore_fbdev_mode+0x31/0x140 [drm_kms_helper] [ 246.745373] drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xb0 [drm_kms_helper] [ 246.746220] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper] [ 246.746884] drm_fb_helper_hotplug_event.part.28+0x96/0xb0 [drm_kms_helper] [ 246.747675] drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper] [ 246.748544] drm_kms_helper_hotplug_event+0x2a/0x30 [drm_kms_helper] [ 246.749439] nv50_mstm_hotplug+0x15/0x20 [nouveau] [ 246.750111] drm_dp_send_link_address+0x177/0x1c0 [drm_kms_helper] [ 246.750764] drm_dp_check_and_send_link_address+0xa8/0xd0 [drm_kms_helper] [ 246.751602] drm_dp_mst_link_probe_work+0x51/0x90 [drm_kms_helper] [ 246.752314] process_one_work+0x231/0x620 [ 246.752979] worker_thread+0x44/0x3a0 [ 246.753838] kthread+0x12b/0x150 [ 246.754619] ? wq_pool_ids_show+0x140/0x140 [ 246.755386] ? kthread_create_worker_on_cpu+0x70/0x70 [ 246.756162] ret_from_fork+0x3a/0x50 [ 246.756847] Showing all locks held in the system: [ 246.758261] 3 locks held by kworker/4:0/37: [ 246.759016] #0: 00000000f8df4d2d ((wq_completion)"events"){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.759856] #1: 00000000e6065461 ((work_completion)(&(&dev->mode_config.output_poll_work)->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.760670] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.761516] 2 locks held by kworker/0:1/60: [ 246.762274] #0: 00000000fff6be0f ((wq_completion)"pm"){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.762982] #1: 000000005ab44fb4 ((work_completion)(&dev->power.work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.763890] 1 lock held by khungtaskd/64: [ 246.764664] #0: 000000008cb8b5c3 (rcu_read_lock){....}, at: debug_show_all_locks+0x23/0x185 [ 246.765588] 5 locks held by kworker/4:2/422: [ 246.766440] #0: 00000000232f0959 ((wq_completion)"events_long"){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] [ 246.770839] 1 lock held by dmesg/1038: [ 246.771739] 2 locks held by zsh/1172: [ 246.772650] #0: 00000000836d0438 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 246.773680] #1: 000000001f4f4d48 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0xc1/0x870 [ 246.775522] ============================================= After trying dozens of different solutions, I found one very simple one that should also have the benefit of preventing us from having to fight locking for the rest of our lives. So, we work around these deadlocks by deferring all fbcon hotplug events that happen after the runtime suspend process starts until after the device is resumed again. Changes since v7: - Fixup commit message - Daniel Vetter Changes since v6: - Remove unused nouveau_fbcon_hotplugged_in_suspend() - Ilia Changes since v5: - Come up with the (hopefully final) solution for solving this dumb problem, one that is a lot less likely to cause issues with locking in the future. This should work around all deadlock conditions with fbcon brought up thus far. Changes since v4: - Add nouveau_fbcon_hotplugged_in_suspend() to workaround deadlock condition that Lukas described - Just move all of this out of drm_fb_helper. It seems that other DRM drivers have already figured out other workarounds for this. If other drivers do end up needing this in the future, we can just move this back into drm_fb_helper again. Changes since v3: - Actually check if fb_helper is NULL in both new helpers - Actually check drm_fbdev_emulation in both new helpers - Don't fire off a fb_helper hotplug unconditionally; only do it if the following conditions are true (as otherwise, calling this in the wrong spot will cause Bad Things to happen): - fb_helper hotplug handling was actually inhibited previously - fb_helper actually has a delayed hotplug pending - fb_helper is actually bound - fb_helper is actually initialized - Add __must_check to drm_fb_helper_suspend_hotplug(). There's no situation where a driver would actually want to use this without checking the return value, so enforce that - Rewrite and clarify the documentation for both helpers. - Make sure to return true in the drm_fb_helper_suspend_hotplug() stub that's provided in drm_fb_helper.h when CONFIG_DRM_FBDEV_EMULATION isn't enabled - Actually grab the toplevel fb_helper lock in drm_fb_helper_resume_hotplug(), since it's possible other activity (such as a hotplug) could be going on at the same time the driver calls drm_fb_helper_resume_hotplug(). We need this to check whether or not drm_fb_helper_hotplug_event() needs to be called anyway Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Karol Herbst <kherbst@redhat.com> Acked-by: Daniel Vetter <daniel@ffwll.ch> Cc: stable@vger.kernel.org Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ben Skeggs <bskeggs@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

…_values fails [ Upstream commit 7915919 ] Fixes a use-after-free reported by KASAN when later iscsi_target_login_sess_out gets called and it tries to access conn->sess->se_sess: Disabling lock debugging due to kernel taint iSCSI Login timeout on Network Portal [::]:3260 iSCSI Login negotiation failed. ================================================================== BUG: KASAN: use-after-free in iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] Read of size 8 at addr ffff880109d070c8 by task iscsi_np/980 CPU: 1 PID: 980 Comm: iscsi_np Tainted: G O 4.17.8kasan.sess.connops+ #4 Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 05/19/2014 Call Trace: dump_stack+0x71/0xac print_address_description+0x65/0x22e ? iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] kasan_report.cold.6+0x241/0x2fd iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod] iscsi_target_login_thread+0x1086/0x1710 [iscsi_target_mod] ? __sched_text_start+0x8/0x8 ? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod] ? __kthread_parkme+0xcc/0x100 ? parse_args.cold.14+0xd3/0xd3 ? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod] kthread+0x1a0/0x1c0 ? kthread_bind+0x30/0x30 ret_from_fork+0x35/0x40 Allocated by task 980: kasan_kmalloc+0xbf/0xe0 kmem_cache_alloc_trace+0x112/0x210 iscsi_target_login_thread+0x816/0x1710 [iscsi_target_mod] kthread+0x1a0/0x1c0 ret_from_fork+0x35/0x40 Freed by task 980: __kasan_slab_free+0x125/0x170 kfree+0x90/0x1d0 iscsi_target_login_thread+0x1577/0x1710 [iscsi_target_mod] kthread+0x1a0/0x1c0 ret_from_fork+0x35/0x40 The buggy address belongs to the object at ffff880109d06f00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 456 bytes inside of 512-byte region [ffff880109d06f00, ffff880109d07100) The buggy address belongs to the page: page:ffffea0004274180 count:1 mapcount:0 mapping:0000000000000000 index:0x0 compound_mapcount: 0 flags: 0x17fffc000008100(slab|head) raw: 017fffc000008100 0000000000000000 0000000000000000 00000001000c000c raw: dead000000000100 dead000000000200 ffff88011b002e00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880109d06f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880109d07000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880109d07080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880109d07100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff880109d07180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com> [rebased against idr/ida changes and to handle ret review comments from Matthew] Signed-off-by: Mike Christie <mchristi@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Reviewed-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3941552 upstream. Currently the size of hypercall buffers allocated via /dev/xen/hypercall is limited to a default of 64 memory pages. For live migration of guests this might be too small as the page dirty bitmask needs to be sized according to the size of the guest. This means migrating a 8GB sized guest is already exhausting the default buffer size for the dirty bitmap. There is no sensible way to set a sane limit, so just remove it completely. The device node's usage is limited to root anyway, so there is no additional DOS scenario added by allowing unlimited buffers. While at it make the error path for the -ENOMEM case a little bit cleaner by setting n_pages to the number of successfully allocated pages instead of the target size. Fixes: c51b3c6 ("xen: add new hypercall buffer mapping device") Cc: <stable@vger.kernel.org> #4.18 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c495144 upstream. We're getting a lockdep splat because we take the dio_sem under the log_mutex. What we really need is to protect fsync() from logging an extent map for an extent we never waited on higher up, so just guard the whole thing with dio_sem. ====================================================== WARNING: possible circular locking dependency detected 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 torvalds#411 Not tainted ------------------------------------------------------ aio-dio-invalid/30928 is trying to acquire lock: 0000000092621cfd (&mm->mmap_sem){++++}, at: get_user_pages_unlocked+0x5a/0x1e0 but task is already holding lock: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&ei->dio_sem){++++}: lock_acquire+0xbd/0x220 down_write+0x51/0xb0 btrfs_log_changed_extents+0x80/0xa40 btrfs_log_inode+0xbaf/0x1000 btrfs_log_inode_parent+0x26f/0xa80 btrfs_log_dentry_safe+0x50/0x70 btrfs_sync_file+0x357/0x540 do_fsync+0x38/0x60 __ia32_sys_fdatasync+0x12/0x20 do_fast_syscall_32+0x9a/0x2f0 entry_SYSENTER_compat+0x84/0x96 -> #4 (&ei->log_mutex){+.+.}: lock_acquire+0xbd/0x220 __mutex_lock+0x86/0xa10 btrfs_record_unlink_dir+0x2a/0xa0 btrfs_unlink+0x5a/0xc0 vfs_unlink+0xb1/0x1a0 do_unlinkat+0x264/0x2b0 do_fast_syscall_32+0x9a/0x2f0 entry_SYSENTER_compat+0x84/0x96 -> #3 (sb_internal#2){.+.+}: lock_acquire+0xbd/0x220 __sb_start_write+0x14d/0x230 start_transaction+0x3e6/0x590 btrfs_evict_inode+0x475/0x640 evict+0xbf/0x1b0 btrfs_run_delayed_iputs+0x6c/0x90 cleaner_kthread+0x124/0x1a0 kthread+0x106/0x140 ret_from_fork+0x3a/0x50 -> #2 (&fs_info->cleaner_delayed_iput_mutex){+.+.}: lock_acquire+0xbd/0x220 __mutex_lock+0x86/0xa10 btrfs_alloc_data_chunk_ondemand+0x197/0x530 btrfs_check_data_free_space+0x4c/0x90 btrfs_delalloc_reserve_space+0x20/0x60 btrfs_page_mkwrite+0x87/0x520 do_page_mkwrite+0x31/0xa0 __handle_mm_fault+0x799/0xb00 handle_mm_fault+0x7c/0xe0 __do_page_fault+0x1d3/0x4a0 async_page_fault+0x1e/0x30 -> #1 (sb_pagefaults){.+.+}: lock_acquire+0xbd/0x220 __sb_start_write+0x14d/0x230 btrfs_page_mkwrite+0x6a/0x520 do_page_mkwrite+0x31/0xa0 __handle_mm_fault+0x799/0xb00 handle_mm_fault+0x7c/0xe0 __do_page_fault+0x1d3/0x4a0 async_page_fault+0x1e/0x30 -> #0 (&mm->mmap_sem){++++}: __lock_acquire+0x42e/0x7a0 lock_acquire+0xbd/0x220 down_read+0x48/0xb0 get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_fast+0xa4/0x150 iov_iter_get_pages+0xc3/0x340 do_direct_IO+0xf93/0x1d70 __blockdev_direct_IO+0x32d/0x1c20 btrfs_direct_IO+0x227/0x400 generic_file_direct_write+0xcf/0x180 btrfs_file_write_iter+0x308/0x58c aio_write+0xf8/0x1d0 io_submit_one+0x3a9/0x620 __ia32_compat_sys_io_submit+0xb2/0x270 do_int80_syscall_32+0x5b/0x1a0 entry_INT80_compat+0x88/0xa0 other info that might help us debug this: Chain exists of: &mm->mmap_sem --> &ei->log_mutex --> &ei->dio_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->dio_sem); lock(&ei->log_mutex); lock(&ei->dio_sem); lock(&mm->mmap_sem); *** DEADLOCK *** 1 lock held by aio-dio-invalid/30928: #0: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400 stack backtrace: CPU: 0 PID: 30928 Comm: aio-dio-invalid Not tainted 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 torvalds#411 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Call Trace: dump_stack+0x7c/0xbb print_circular_bug.isra.37+0x297/0x2a4 check_prev_add.constprop.45+0x781/0x7a0 ? __lock_acquire+0x42e/0x7a0 validate_chain.isra.41+0x7f0/0xb00 __lock_acquire+0x42e/0x7a0 lock_acquire+0xbd/0x220 ? get_user_pages_unlocked+0x5a/0x1e0 down_read+0x48/0xb0 ? get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_fast+0xa4/0x150 iov_iter_get_pages+0xc3/0x340 do_direct_IO+0xf93/0x1d70 ? __alloc_workqueue_key+0x358/0x490 ? __blockdev_direct_IO+0x14b/0x1c20 __blockdev_direct_IO+0x32d/0x1c20 ? btrfs_run_delalloc_work+0x40/0x40 ? can_nocow_extent+0x490/0x490 ? kvm_clock_read+0x1f/0x30 ? can_nocow_extent+0x490/0x490 ? btrfs_run_delalloc_work+0x40/0x40 btrfs_direct_IO+0x227/0x400 ? btrfs_run_delalloc_work+0x40/0x40 generic_file_direct_write+0xcf/0x180 btrfs_file_write_iter+0x308/0x58c aio_write+0xf8/0x1d0 ? kvm_clock_read+0x1f/0x30 ? __might_fault+0x3e/0x90 io_submit_one+0x3a9/0x620 ? io_submit_one+0xe5/0x620 __ia32_compat_sys_io_submit+0xb2/0x270 do_int80_syscall_32+0x5b/0x1a0 entry_INT80_compat+0x88/0xa0 CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7c388f9 upstream. Remove stale debug trace. Fixes: 1eb42f9 ("qla2xxx: Make trace flags more readable") Cc: stable@vger.kernel.org #4.10 Signed-off-by: Quinn Tran <quinn.tran@cavium.com> Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1e4ac5d upstream. If chip unable to fully initialize, use full shutdown sequence to clear out any stale FW state. Fixes: e315cd2 ("[SCSI] qla2xxx: Code changes for qla data structure refactoring") Cc: stable@vger.kernel.org #4.10 Signed-off-by: Quinn Tran <quinn.tran@cavium.com> Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6b04114 upstream. By default NFSv3 doesn't support ACL (Access Control Lists) which might be quite convenient to have so that mounted NFS behaves exactly as any other local file-system. In particular missing support of ACL makes umask useless. This among other thigs fixes Glibc's "nptl/tst-umask1". Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Cupertino Miranda <cmiranda@synopsys.com> Cc: stable@vger.kernel.org #4.14+ Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit c5a94f4 ] It was observed that a process blocked indefintely in __fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP to be cleared via fscache_wait_for_deferred_lookup(). At this time, ->backing_objects was empty, which would normaly prevent __fscache_read_or_alloc_page() from getting to the point of waiting. This implies that ->backing_objects was cleared *after* __fscache_read_or_alloc_page was was entered. When an object is "killed" and then "dropped", FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is ->backing_objects cleared. This leaves a window where something else can set FSCACHE_COOKIE_LOOKING_UP and __fscache_read_or_alloc_page() can start waiting, before ->backing_objects is cleared There is some uncertainty in this analysis, but it seems to be fit the observations. Adding the wake in this patch will be handled correctly by __fscache_read_or_alloc_page(), as it checks if ->backing_objects is empty again, after waiting. Customer which reported the hang, also report that the hang cannot be reproduced with this fix. The backtrace for the blocked process looked like: PID: 29360 TASK: ffff881ff2ac0f80 CPU: 3 COMMAND: "zsh" #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache] #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache] #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs] torvalds#7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs] torvalds#8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73 torvalds#9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs] torvalds#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756 torvalds#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa torvalds#12 [ffff881ff43eff18] sys_read at ffffffff811fda62 torvalds#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit eca1e56 upstream. Old firmware versions don't support this command. Sending it to any firmware before -41.ucode will crash the firmware. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=201975 Fixes: 66e8390 ("iwlwifi: fix wrong WGDS_WIFI_DATA_SIZE") CC: <stable@vger.kernel.org> #4.19+ Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 7d033c9 ] This patch makes sure the flow label in the IPv6 header forged in ipv6_local_error() is initialized. BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32 CPU: 1 PID: 24675 Comm: syz-executor1 Not tainted 4.20.0-rc7+ #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x173/0x1d0 lib/dump_stack.c:113 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613 kmsan_internal_check_memory+0x455/0xb00 mm/kmsan/kmsan.c:675 kmsan_copy_to_user+0xab/0xc0 mm/kmsan/kmsan_hooks.c:601 _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32 copy_to_user include/linux/uaccess.h:177 [inline] move_addr_to_user+0x2e9/0x4f0 net/socket.c:227 ___sys_recvmsg+0x5d7/0x1140 net/socket.c:2284 __sys_recvmsg net/socket.c:2327 [inline] __do_sys_recvmsg net/socket.c:2337 [inline] __se_sys_recvmsg+0x2fa/0x450 net/socket.c:2334 __x64_sys_recvmsg+0x4a/0x70 net/socket.c:2334 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x457ec9 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f8750c06c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 0000000000002000 RSI: 0000000020000400 RDI: 0000000000000005 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8750c076d4 R13: 00000000004c4a60 R14: 00000000004d8140 R15: 00000000ffffffff Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:204 [inline] kmsan_save_stack mm/kmsan/kmsan.c:219 [inline] kmsan_internal_chain_origin+0x134/0x230 mm/kmsan/kmsan.c:439 __msan_chain_origin+0x70/0xe0 mm/kmsan/kmsan_instr.c:200 ipv6_recv_error+0x1e3f/0x1eb0 net/ipv6/datagram.c:475 udpv6_recvmsg+0x398/0x2ab0 net/ipv6/udp.c:335 inet_recvmsg+0x4fb/0x600 net/ipv4/af_inet.c:830 sock_recvmsg_nosec net/socket.c:794 [inline] sock_recvmsg+0x1d1/0x230 net/socket.c:801 ___sys_recvmsg+0x4d5/0x1140 net/socket.c:2278 __sys_recvmsg net/socket.c:2327 [inline] __do_sys_recvmsg net/socket.c:2337 [inline] __se_sys_recvmsg+0x2fa/0x450 net/socket.c:2334 __x64_sys_recvmsg+0x4a/0x70 net/socket.c:2334 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:204 [inline] kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:158 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2759 [inline] __kmalloc_node_track_caller+0xe18/0x1030 mm/slub.c:4383 __kmalloc_reserve net/core/skbuff.c:137 [inline] __alloc_skb+0x309/0xa20 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:998 [inline] ipv6_local_error+0x1a7/0x9e0 net/ipv6/datagram.c:334 __ip6_append_data+0x129f/0x4fd0 net/ipv6/ip6_output.c:1311 ip6_make_skb+0x6cc/0xcf0 net/ipv6/ip6_output.c:1775 udpv6_sendmsg+0x3f8e/0x45d0 net/ipv6/udp.c:1384 inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] __sys_sendto+0x8c4/0xac0 net/socket.c:1788 __do_sys_sendto net/socket.c:1800 [inline] __se_sys_sendto+0x107/0x130 net/socket.c:1796 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Bytes 4-7 of 28 are uninitialized Memory access of size 28 starts at ffff8881937bfce0 Data copied to user address 0000000020000000 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 4f4b374 ] This is the much more correct fix for my earlier attempt at: https://lkml.org/lkml/2018/12/10/118 Short recap: - There's not actually a locking issue, it's just lockdep being a bit too eager to complain about a possible deadlock. - Contrary to what I claimed the real problem is recursion on kn->count. Greg pointed me at sysfs_break_active_protection(), used by the scsi subsystem to allow a sysfs file to unbind itself. That would be a real deadlock, which isn't what's happening here. Also, breaking the active protection means we'd need to manually handle all the lifetime fun. - With Rafael we discussed the task_work approach, which kinda works, but has two downsides: It's a functional change for a lockdep annotation issue, and it won't work for the bind file (which needs to get the errno from the driver load function back to userspace). - Greg also asked why this never showed up: To hit this you need to unregister a 2nd driver from the unload code of your first driver. I guess only gpus do that. The bug has always been there, but only with a recent patch series did we add more locks so that lockdep built a chain from unbinding the snd-hda driver to the acpi_video_unregister call. Full lockdep splat: [12301.898799] ============================================ [12301.898805] WARNING: possible recursive locking detected [12301.898811] 4.20.0-rc7+ torvalds#84 Not tainted [12301.898815] -------------------------------------------- [12301.898821] bash/5297 is trying to acquire lock: [12301.898826] 00000000f61c6093 (kn->count#39){++++}, at: kernfs_remove_by_name_ns+0x3b/0x80 [12301.898841] but task is already holding lock: [12301.898847] 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190 [12301.898856] other info that might help us debug this: [12301.898862] Possible unsafe locking scenario: [12301.898867] CPU0 [12301.898870] ---- [12301.898874] lock(kn->count#39); [12301.898879] lock(kn->count#39); [12301.898883] *** DEADLOCK *** [12301.898891] May be due to missing lock nesting notation [12301.898899] 5 locks held by bash/5297: [12301.898903] #0: 00000000cd800e54 (sb_writers#4){.+.+}, at: vfs_write+0x17f/0x1b0 [12301.898915] #1: 000000000465e7c2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xd3/0x190 [12301.898925] #2: 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190 [12301.898936] #3: 00000000414ef7ac (&dev->mutex){....}, at: device_release_driver_internal+0x34/0x240 [12301.898950] #4: 000000003218fbdf (register_count_mutex){+.+.}, at: acpi_video_unregister+0xe/0x40 [12301.898960] stack backtrace: [12301.898968] CPU: 1 PID: 5297 Comm: bash Not tainted 4.20.0-rc7+ torvalds#84 [12301.898974] Hardware name: Hewlett-Packard HP EliteBook 8460p/161C, BIOS 68SCF Ver. F.01 03/11/2011 [12301.898982] Call Trace: [12301.898989] dump_stack+0x67/0x9b [12301.898997] __lock_acquire+0x6ad/0x1410 [12301.899003] ? kernfs_remove_by_name_ns+0x3b/0x80 [12301.899010] ? find_held_lock+0x2d/0x90 [12301.899017] ? mutex_spin_on_owner+0xe4/0x150 [12301.899023] ? find_held_lock+0x2d/0x90 [12301.899030] ? lock_acquire+0x90/0x180 [12301.899036] lock_acquire+0x90/0x180 [12301.899042] ? kernfs_remove_by_name_ns+0x3b/0x80 [12301.899049] __kernfs_remove+0x296/0x310 [12301.899055] ? kernfs_remove_by_name_ns+0x3b/0x80 [12301.899060] ? kernfs_name_hash+0xd/0x80 [12301.899066] ? kernfs_find_ns+0x6c/0x100 [12301.899073] kernfs_remove_by_name_ns+0x3b/0x80 [12301.899080] bus_remove_driver+0x92/0xa0 [12301.899085] acpi_video_unregister+0x24/0x40 [12301.899127] i915_driver_unload+0x42/0x130 [i915] [12301.899160] i915_pci_remove+0x19/0x30 [i915] [12301.899169] pci_device_remove+0x36/0xb0 [12301.899176] device_release_driver_internal+0x185/0x240 [12301.899183] unbind_store+0xaf/0x180 [12301.899189] kernfs_fop_write+0x104/0x190 [12301.899195] __vfs_write+0x31/0x180 [12301.899203] ? rcu_read_lock_sched_held+0x6f/0x80 [12301.899209] ? rcu_sync_lockdep_assert+0x29/0x50 [12301.899216] ? __sb_start_write+0x13c/0x1a0 [12301.899221] ? vfs_write+0x17f/0x1b0 [12301.899227] vfs_write+0xb9/0x1b0 [12301.899233] ksys_write+0x50/0xc0 [12301.899239] do_syscall_64+0x4b/0x180 [12301.899247] entry_SYSCALL_64_after_hwframe+0x49/0xbe [12301.899253] RIP: 0033:0x7f452ac7f7a4 [12301.899259] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 aa f0 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83 [12301.899273] RSP: 002b:00007ffceafa6918 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [12301.899282] RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f452ac7f7a4 [12301.899288] RDX: 000000000000000d RSI: 00005612a1abf7c0 RDI: 0000000000000001 [12301.899295] RBP: 00005612a1abf7c0 R08: 000000000000000a R09: 00005612a1c46730 [12301.899301] R10: 000000000000000a R11: 0000000000000246 R12: 000000000000000d [12301.899308] R13: 0000000000000001 R14: 00007f452af4a740 R15: 000000000000000d Looking around I've noticed that usb and i2c already handle similar recursion problems, where a sysfs file can unbind the same type of sysfs somewhere else in the hierarchy. Relevant commits are: commit 356c05d Author: Alan Stern <stern@rowland.harvard.edu> Date: Mon May 14 13:30:03 2012 -0400 sysfs: get rid of some lockdep false positives commit e9b526f Author: Alexander Sverdlin <alexander.sverdlin@nsn.com> Date: Fri May 17 14:56:35 2013 +0200 i2c: suppress lockdep warning on delete_device Implement the same trick for driver bind/unbind. v2: Put the macro into bus.c (Greg). Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Ramalingam C <ramalingam.c@intel.com> Cc: Arend van Spriel <aspriel@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Bartosz Golaszewski <brgl@bgdev.pl> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: Vivek Gautam <vivek.gautam@codeaurora.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 1629db9 upstream. In case a command which completes in Command Status was sent using the hci_cmd_send-family of APIs there would be a misleading error in the hci_get_cmd_complete function, since the code would be trying to fetch the Command Complete parameters when there are none. Avoid the misleading error and silently bail out from the function in case the received event is a command status. Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> Acked-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Tested-by Adam Ford <aford173@gmail.com> #4.19.16 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e6a72b7 upstream. ARCv2 optimized memset uses PREFETCHW instruction for prefetching the next cache line but doesn't ensure that the line is not past the end of the buffer. PRETECHW changes the line ownership and marks it dirty, which can cause issues in SMP config when next line was already owned by other core. Fix the issue by avoiding the PREFETCHW Some more details: The current code has 3 logical loops (ignroing the unaligned part) (a) Big loop for doing aligned 64 bytes per iteration with PREALLOC (b) Loop for 32 x 2 bytes with PREFETCHW (c) any left over bytes loop (a) was already eliding the last 64 bytes, so PREALLOC was safe. The fix was removing PREFETCW from (b). Another potential issue (applicable to configs with 32 or 128 byte L1 cache line) is that PREALLOC assumes 64 byte cache line and may not do the right thing specially for 32b. While it would be easy to adapt, there are no known configs with those lie sizes, so for now, just compile out PREALLOC in such cases. Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Cc: stable@vger.kernel.org #4.4+ Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: rewrote changelog, used asm .macro vs. "C" macro] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a3010a0 upstream. In setup_arch_memory we reserve the memory area wherein the kernel is located. Current implementation may reserve more memory than it actually required in case of CONFIG_LINUX_LINK_BASE is not equal to CONFIG_LINUX_RAM_BASE. This happens because we calculate start of the reserved region relatively to the CONFIG_LINUX_RAM_BASE and end of the region relatively to the CONFIG_LINUX_RAM_BASE. For example in case of HSDK board we wasted 256MiB of physical memory: ------------------->8------------------------------ Memory: 770416K/1048576K available (5496K kernel code, 240K rwdata, 1064K rodata, 2200K init, 275K bss, 278160K reserved, 0K cma-reserved) ------------------->8------------------------------ Fix that. Fixes: 9ed6878 ("ARC: mm: Decouple RAM base address from kernel link addr") Cc: stable@vger.kernel.org #4.14+ Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 2122b40 ] When unregistering fbdev using unregister_framebuffer(), any bound console will unbind automatically. This is working fine if this is the only framebuffer, resulting in a switch to the dummy console. However if there is a fb0 and I unregister fb1 having a bound console, I eventually get a crash. The fastest way for me to trigger the crash is to do a reboot, resulting in this splat: [ 76.478825] WARNING: CPU: 0 PID: 527 at linux/kernel/workqueue.c:1442 __queue_work+0x2d4/0x41c [ 76.478849] Modules linked in: raspberrypi_hwmon gpio_backlight backlight bcm2835_rng rng_core [last unloaded: tinydrm] [ 76.478916] CPU: 0 PID: 527 Comm: systemd-udevd Not tainted 4.20.0-rc4+ #4 [ 76.478933] Hardware name: BCM2835 [ 76.478949] Backtrace: [ 76.478995] [<c010d388>] (dump_backtrace) from [<c010d670>] (show_stack+0x20/0x24) [ 76.479022] r6:00000000 r5:c0bc73be r4:00000000 r3:6fb5bf81 [ 76.479060] [<c010d650>] (show_stack) from [<c08e82f4>] (dump_stack+0x20/0x28) [ 76.479102] [<c08e82d4>] (dump_stack) from [<c0120070>] (__warn+0xec/0x12c) [ 76.479134] [<c011ff84>] (__warn) from [<c01201e4>] (warn_slowpath_null+0x4c/0x58) [ 76.479165] r9:c0eb6944 r8:00000001 r7:c0e927f8 r6:c0bc73be r5:000005a2 r4:c0139e84 [ 76.479197] [<c0120198>] (warn_slowpath_null) from [<c0139e84>] (__queue_work+0x2d4/0x41c) [ 76.479222] r6:d7666a00 r5:c0e918ee r4:dbc4e700 [ 76.479251] [<c0139bb0>] (__queue_work) from [<c013a02c>] (queue_work_on+0x60/0x88) [ 76.479281] r10:c0496bf8 r9:00000100 r8:c0e92ae0 r7:00000001 r6:d9403700 r5:d7666a00 [ 76.479298] r4:20000113 [ 76.479348] [<c0139fcc>] (queue_work_on) from [<c0496c28>] (cursor_timer_handler+0x30/0x54) [ 76.479374] r7:d8a8fabc r6:c0e08088 r5:d8afdc5c r4:d8a8fabc [ 76.479413] [<c0496bf8>] (cursor_timer_handler) from [<c0178744>] (call_timer_fn+0x100/0x230) [ 76.479435] r4:c0e9192f r3:d758a340 [ 76.479465] [<c0178644>] (call_timer_fn) from [<c0178980>] (expire_timers+0x10c/0x12c) [ 76.479495] r10:40000000 r9:c0e9192f r8:c0e92ae0 r7:d8afdccc r6:c0e19280 r5:c0496bf8 [ 76.479513] r4:d8a8fabc [ 76.479541] [<c0178874>] (expire_timers) from [<c0179630>] (run_timer_softirq+0xa8/0x184) [ 76.479570] r9:00000001 r8:c0e19280 r7:00000000 r6:c0e08088 r5:c0e1a3e0 r4:c0e19280 [ 76.479603] [<c0179588>] (run_timer_softirq) from [<c0102404>] (__do_softirq+0x1ac/0x3fc) [ 76.479632] r10:c0e91680 r9:d8afc020 r8:0000000a r7:00000100 r6:00000001 r5:00000002 [ 76.479650] r4:c0eb65ec [ 76.479686] [<c0102258>] (__do_softirq) from [<c0124d10>] (irq_exit+0xe8/0x168) [ 76.479716] r10:d8d1a9b0 r9:d8afc000 r8:00000001 r7:d949c000 r6:00000000 r5:c0e8b3f0 [ 76.479734] r4:00000000 [ 76.479764] [<c0124c28>] (irq_exit) from [<c016b72c>] (__handle_domain_irq+0x94/0xb0) [ 76.479793] [<c016b698>] (__handle_domain_irq) from [<c01021dc>] (bcm2835_handle_irq+0x3c/0x48) [ 76.479823] r8:d8afdebc r7:d8afddfc r6:ffffffff r5:c0e089f8 r4:d8afddc8 r3:d8afddc8 [ 76.479851] [<c01021a0>] (bcm2835_handle_irq) from [<c01019f0>] (__irq_svc+0x70/0x98) The problem is in the console rebinding in fbcon_fb_unbind(). It uses the virtual console index as the new framebuffer index to bind the console(s) to. The correct way is to use the con2fb_map lookup table to find the framebuffer index. Fixes: cfafca8 ("fbdev: fbcon: console unregistration from unregister_framebuffer") Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 6347244 ] Since __sanitizer_cov_trace_const_cmp4 is marked as notrace, the function called from __sanitizer_cov_trace_const_cmp4 shouldn't be traceable either. ftrace_graph_caller() gets called every time func write_comp_data() gets called if it isn't marked 'notrace'. This is the backtrace from gdb: #0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 #1 0xffffff8010201920 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151 #2 0xffffff8010439714 in write_comp_data (type=5, arg1=0, arg2=0, ip=18446743524224276596) at ../kernel/kcov.c:116 #3 0xffffff8010439894 in __sanitizer_cov_trace_const_cmp4 (arg1=<optimized out>, arg2=<optimized out>) at ../kernel/kcov.c:188 #4 0xffffff8010201874 in prepare_ftrace_return (self_addr=18446743524226602768, parent=0xffffff801014b918, frame_pointer=18446743524223531344) at ./include/generated/atomic-instrumented.h:27 #5 0xffffff801020194c in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182 Rework so that write_comp_data() that are called from __sanitizer_cov_trace_*_cmp*() are marked as 'notrace'. Commit 903e8ff ("kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace") missed to mark write_comp_data() as 'notrace'. When that patch was created gcc-7 was used. In lib/Kconfig.debug config KCOV_ENABLE_COMPARISONS depends on $(cc-option,-fsanitize-coverage=trace-cmp) That code path isn't hit with gcc-7. However, it were that with gcc-8. Link: http://lkml.kernel.org/r/20181206143011.23719-1-anders.roxell@linaro.org Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Co-developed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 252f6e8 upstream. It is currently done in arc_init_IRQ() which might be too late considering gcc 7.3.1 onwards (GNU 2018.03) generates unaligned memory accesses by default Cc: stable@vger.kernel.org #4.4+ Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: rewrote changelog] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

wildea01 and others added 30 commits January 5, 2018 22:47

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Rpk v4.14 meltdown spectre mitigations #4

Rpk v4.14 meltdown spectre mitigations #4

ardbiesheuvel commented Jan 5, 2018

Rpk v4.14 meltdown spectre mitigations #4

Rpk v4.14 meltdown spectre mitigations #4

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ardbiesheuvel commented Jan 5, 2018