Re: WARNING: suspicious RCU usage in io_init_identity

[Jens Axboe]

On 10/16/20 9:02 AM, Qian Cai wrote:
> On Fri, 2020-10-16 at 01:12 -0700, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit:    b2926c10 Add linux-next specific files for 20201016
>> git tree:       linux-next
>> console output: https://syzkaller.appspot.com/x/log.txt?x=12fc877f900000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=6160209582f55fb1
>> dashboard link: https://syzkaller.appspot.com/bug?extid=4596e1fcf98efa7d1745
>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+4596e1fcf98efa7d1745@xxxxxxxxxxxxxxxxxxxxxxxxx
>>
>> =============================
>> WARNING: suspicious RCU usage
>> 5.9.0-next-20201016-syzkaller #0 Not tainted
>> -----------------------------
>> include/linux/cgroup.h:494 suspicious rcu_dereference_check() usage!
> 
> Introduced by the linux-next commits:
> 
> 07950f53f85b ("io_uring: COW io_identity on mismatch")
> 
> Can't find the patchset was posted anywhere. Anyway, this should fix it? 

It's just in testing... I already folded in this change.

-- 
Jens Axboe