Hello, syzbot found the following crash on: HEAD commit: b2e2a818 Add linux-next specific files for 20200406 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1418a1c7e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=595413e7170f444b dashboard link: https://syzkaller.appspot.com/bug?extid=e6eeca4a035da76b3065 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17cd89cde00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=102d89cde00000 The bug was bisected to: commit 0558955373023b08f638c9ede36741b0e4200f58 Author: Xiaoguang Wang <xiaoguang.wang@xxxxxxxxxxxxxxxxx> Date: Tue Mar 31 06:05:18 2020 +0000 io_uring: refactor file register/unregister/update handling bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=166f91c7e00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=156f91c7e00000 console output: https://syzkaller.appspot.com/x/log.txt?x=116f91c7e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+e6eeca4a035da76b3065@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 055895537302 ("io_uring: refactor file register/unregister/update handling") INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 7099 Comm: syz-executor897 Not tainted 5.6.0-next-20200406-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 assign_lock_key kernel/locking/lockdep.c:913 [inline] register_lock_class+0x1664/0x1760 kernel/locking/lockdep.c:1225 __lock_acquire+0x104/0x4e00 kernel/locking/lockdep.c:4223 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 io_sqe_files_register fs/io_uring.c:6599 [inline] __io_uring_register+0x1fe8/0x2f00 fs/io_uring.c:8001 __do_sys_io_uring_register fs/io_uring.c:8081 [inline] __se_sys_io_uring_register fs/io_uring.c:8063 [inline] __x64_sys_io_uring_register+0x192/0x560 fs/io_uring.c:8063 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x440289 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffff1bbf558 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440289 RDX: 0000000020000280 RSI: 0000000000000002 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000401b10 R13: 0000000000401ba0 R14: 0000000000000000 R15: 0000000000000000 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches