Re: WARNING in percpu_ref_exit (2)

Re: WARNING in percpu_ref_exit (2)

[syzbot]

syzbot has bisected this bug to:

commit cbb537634780172137459dead490d668d437ef4d
Author: Jens Axboe <axboe@kernel.dk>
Date:   Mon Dec 9 18:22:50 2019 +0000

     io_uring: avoid ring quiesce for fixed file set unregister and update

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1118aac1e00000
start commit:   7ddd09fc Add linux-next specific files for 20191220
git tree:       linux-next
final crash:    https://syzkaller.appspot.com/x/report.txt?x=1318aac1e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1518aac1e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f183b01c3088afc6
dashboard link: https://syzkaller.appspot.com/bug?extid=8c4a14856e657b43487c
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14b8f351e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14b51925e00000

Reported-by: syzbot+8c4a14856e657b43487c@syzkaller.appspotmail.com
Fixes: cbb537634780 ("io_uring: avoid ring quiesce for fixed file set  
unregister and update")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: WARNING in percpu_ref_exit (2)

[syzbot]

syzbot suspects this issue was fixed by commit:

commit c1e2148f8ecb26863b899d402a823dab8e26efd1
Author: Jens Axboe <axboe@kernel.dk>
Date:   Wed Mar 4 14:25:50 2020 +0000

    io_uring: free fixed_file_data after RCU grace period

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=161ea46e500000
start commit:   63849c8f Merge tag 'linux-kselftest-5.6-rc5' of git://git...
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=4527d1e2fb19fd5c
dashboard link: https://syzkaller.appspot.com/bug?extid=8c4a14856e657b43487c
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13c30061e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1251b731e00000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: io_uring: free fixed_file_data after RCU grace period

For information about bisection process see: https://goo.gl/tpsmEJ#bisection