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firmware: arm_scmi: Fix slab-use-after-free in scmi_bus_notifier()
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[ Upstream commit 2954160 ]

The scmi_dev->name is released prematurely in __scmi_device_destroy(),
which causes slab-use-after-free when accessing scmi_dev->name in
scmi_bus_notifier(). So move the release of scmi_dev->name to
scmi_device_release() to avoid slab-use-after-free.

  |  BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec
  |  Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1
  |
  |  CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.6.38-debug #1
  |  Hardware name: Qualcomm Technologies, Inc. SA8775P Ride (DT)
  |  Call trace:
  |   dump_backtrace+0x94/0x114
  |   show_stack+0x18/0x24
  |   dump_stack_lvl+0x48/0x60
  |   print_report+0xf4/0x5b0
  |   kasan_report+0xa4/0xec
  |   __asan_report_load1_noabort+0x20/0x2c
  |   strncmp+0xe4/0xec
  |   scmi_bus_notifier+0x5c/0x54c
  |   notifier_call_chain+0xb4/0x31c
  |   blocking_notifier_call_chain+0x68/0x9c
  |   bus_notify+0x54/0x78
  |   device_del+0x1bc/0x840
  |   device_unregister+0x20/0xb4
  |   __scmi_device_destroy+0xac/0x280
  |   scmi_device_destroy+0x94/0xd0
  |   scmi_chan_setup+0x524/0x750
  |   scmi_probe+0x7fc/0x1508
  |   platform_probe+0xc4/0x19c
  |   really_probe+0x32c/0x99c
  |   __driver_probe_device+0x15c/0x3c4
  |   driver_probe_device+0x5c/0x170
  |   __driver_attach+0x1c8/0x440
  |   bus_for_each_dev+0xf4/0x178
  |   driver_attach+0x3c/0x58
  |   bus_add_driver+0x234/0x4d4
  |   driver_register+0xf4/0x3c0
  |   __platform_driver_register+0x60/0x88
  |   scmi_driver_init+0xb0/0x104
  |   do_one_initcall+0xb4/0x664
  |   kernel_init_freeable+0x3c8/0x894
  |   kernel_init+0x24/0x1e8
  |   ret_from_fork+0x10/0x20
  |
  |  Allocated by task 1:
  |   kasan_save_stack+0x2c/0x54
  |   kasan_set_track+0x2c/0x40
  |   kasan_save_alloc_info+0x24/0x34
  |   __kasan_kmalloc+0xa0/0xb8
  |   __kmalloc_node_track_caller+0x6c/0x104
  |   kstrdup+0x48/0x84
  |   kstrdup_const+0x34/0x40
  |   __scmi_device_create.part.0+0x8c/0x408
  |   scmi_device_create+0x104/0x370
  |   scmi_chan_setup+0x2a0/0x750
  |   scmi_probe+0x7fc/0x1508
  |   platform_probe+0xc4/0x19c
  |   really_probe+0x32c/0x99c
  |   __driver_probe_device+0x15c/0x3c4
  |   driver_probe_device+0x5c/0x170
  |   __driver_attach+0x1c8/0x440
  |   bus_for_each_dev+0xf4/0x178
  |   driver_attach+0x3c/0x58
  |   bus_add_driver+0x234/0x4d4
  |   driver_register+0xf4/0x3c0
  |   __platform_driver_register+0x60/0x88
  |   scmi_driver_init+0xb0/0x104
  |   do_one_initcall+0xb4/0x664
  |   kernel_init_freeable+0x3c8/0x894
  |   kernel_init+0x24/0x1e8
  |   ret_from_fork+0x10/0x20
  |
  |  Freed by task 1:
  |   kasan_save_stack+0x2c/0x54
  |   kasan_set_track+0x2c/0x40
  |   kasan_save_free_info+0x38/0x5c
  |   __kasan_slab_free+0xe8/0x164
  |   __kmem_cache_free+0x11c/0x230
  |   kfree+0x70/0x130
  |   kfree_const+0x20/0x40
  |   __scmi_device_destroy+0x70/0x280
  |   scmi_device_destroy+0x94/0xd0
  |   scmi_chan_setup+0x524/0x750
  |   scmi_probe+0x7fc/0x1508
  |   platform_probe+0xc4/0x19c
  |   really_probe+0x32c/0x99c
  |   __driver_probe_device+0x15c/0x3c4
  |   driver_probe_device+0x5c/0x170
  |   __driver_attach+0x1c8/0x440
  |   bus_for_each_dev+0xf4/0x178
  |   driver_attach+0x3c/0x58
  |   bus_add_driver+0x234/0x4d4
  |   driver_register+0xf4/0x3c0
  |   __platform_driver_register+0x60/0x88
  |   scmi_driver_init+0xb0/0x104
  |   do_one_initcall+0xb4/0x664
  |   kernel_init_freeable+0x3c8/0x894
  |   kernel_init+0x24/0x1e8
  |   ret_from_fork+0x10/0x20

Fixes: ee7a9c9 ("firmware: arm_scmi: Add support for multiple device per protocol")
Signed-off-by: Xinqi Zhang <quic_xinqzhan@quicinc.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Message-Id: <20241016-fix-arm-scmi-slab-use-after-free-v2-1-1783685ef90d@quicinc.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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@gregkh
Xinqi Zhang authored and gregkh committed Nov 14, 2024
1 parent 8106155 commit 15b17bb
Showing 1 changed file with 4 additions and 3 deletions.
7 changes: 4 additions & 3 deletions drivers/firmware/arm_scmi/bus.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -305,7 +305,10 @@ EXPORT_SYMBOL_GPL(scmi_driver_unregister);

static void scmi_device_release(struct device *dev)
{
kfree(to_scmi_dev(dev));
struct scmi_device *scmi_dev = to_scmi_dev(dev);

kfree_const(scmi_dev->name);
kfree(scmi_dev);
}

static void __scmi_device_destroy(struct scmi_device *scmi_dev)
Expand All @@ -318,7 +321,6 @@ static void __scmi_device_destroy(struct scmi_device *scmi_dev)
if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
atomic_set(&scmi_syspower_registered, 0);

kfree_const(scmi_dev->name);
ida_free(&scmi_bus_id, scmi_dev->id);
device_unregister(&scmi_dev->dev);
}
Expand Down Expand Up @@ -390,7 +392,6 @@ __scmi_device_create(struct device_node *np, struct device *parent,

return scmi_dev;
put_dev:
kfree_const(scmi_dev->name);
put_device(&scmi_dev->dev);
ida_free(&scmi_bus_id, id);
return NULL;
Expand Down

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