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94e2bd0b25
If a device is getting removed or reprobed during resume, use-after-free
might happen. For example, h5_btrtl_resume() schedules a work queue for
device reprobing, which of course requires removal first.
If the removal happens in parallel with the device_resume() and wins the
race to acquire device_lock(), removal may remove the device from the PM
lists and all, but device_resume() is already running and will continue
when the lock can be acquired, thus calling rfkill_resume().
During this, if rfkill_set_block() is then called after the corresponding
*_unregister() and kfree() are called, there will be an use-after-free
in hci_rfkill_set_block():
BUG: KASAN: use-after-free in hci_rfkill_set_block+0x58/0xc0 [bluetooth]
...
Call trace:
dump_backtrace+0x0/0x154
show_stack+0x20/0x2c
dump_stack+0xbc/0x12c
print_address_description+0x88/0x4b0
__kasan_report+0x144/0x168
kasan_report+0x10/0x18
check_memory_region+0x19c/0x1ac
__kasan_check_write+0x18/0x24
hci_rfkill_set_block+0x58/0xc0 [bluetooth]
rfkill_set_block+0x9c/0x120
rfkill_resume+0x34/0x70
dpm_run_callback+0xf0/0x1f4
device_resume+0x210/0x22c
Fix this by checking rfkill->registered in rfkill_resume(). device_del()
in rfkill_unregister() requires device_lock() and the whole rfkill_resume()
is also protected by the same lock via device_resume(), we can make sure
either the rfkill->registered is false before rfkill_resume() starts or the
rfkill device won't be unregistered before rfkill_resume() returns.
As async_resume() holds a reference to the device, at this level there can
be no use-after-free; only in the user that doesn't expect this scenario.
Fixes:
|
||
|---|---|---|
| .. | ||
| core.c | ||
| input.c | ||
| Kconfig | ||
| Makefile | ||
| rfkill-gpio.c | ||
| rfkill.h | ||