Re: KASAN: use-after-free Read in _free_event

[Alexander Shishkin]

syzbot <syzbot+37100ea87beb0cac28f4@xxxxxxxxxxxxxxxxxxxxxxxxx> writes:

> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+37100ea87beb0cac28f4@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ==================================================================
> BUG: KASAN: use-after-free in atomic_read  
> include/asm-generic/atomic-instrumented.h:26 [inline]
> BUG: KASAN: use-after-free in refcount_sub_and_test_checked+0x87/0x200  
> lib/refcount.c:182
> Read of size 4 at addr ffff88804e9f06e0 by task syz-executor.5/13046

Looks exactly like [1]. There's a proposed fix there, too.

[1] https://marc.info/?l=linux-kernel&m=153111554522295

Regards,
--
Alex