syzbot suspects this issue was fixed by commit: commit c1e2148f8ecb26863b899d402a823dab8e26efd1 Author: Jens Axboe <axboe@xxxxxxxxx> 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