Re: [syzbot] [mm?] WARNING in __put_task_struct (5)

From: Jens Axboe
Date: Wed Jun 18 2025 - 18:49:54 EST


On 6/18/25 4:31 PM, Andrew Morton wrote:
> On Wed, 18 Jun 2025 05:56:30 -0700 syzbot <syzbot+ca15a081ac6b8357d82c@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 4663747812d1 Merge tag 'platform-drivers-x86-v6.16-2' of g..
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=1626f90c580000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=d6f01a06a8393850
>> dashboard link: https://syzkaller.appspot.com/bug?extid=ca15a081ac6b8357d82c
>> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10c9d5d4580000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/ef27ce1c74bb/disk-46637478.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/2962783b1956/vmlinux-46637478.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/faa841f27097/bzImage-46637478.xz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+ca15a081ac6b8357d82c@xxxxxxxxxxxxxxxxxxxxxxxxx
>>
>> RBP: 00007ff5f3810b39 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
>> R13: 0000000000000000 R14: 00007ff5f39b5fa0 R15: 00007ffd192cb478
>> </TASK>
>> ------------[ cut here ]------------
>> WARNING: CPU: 1 PID: 6071 at kernel/fork.c:731 __put_task_struct+0x340/0x530 kernel/fork.c:731
>
> It doesn't look MM related. Perhaps there's something wonky in the
> io_sq_offload_create() error path.

Yeah it's a bug added in this release, already fixed and going upstream
later this week.

#syz dup: [syzbot] [io-uring?] WARNING: ODEBUG bug in io_sq_offload_create

--
Jens Axboe