Hello, syzbot found the following crash on: HEAD commit: ac935d22 Add linux-next specific files for 20200415 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=12deaa5e100000 kernel config: https://syzkaller.appspot.com/x/.config?x=bc498783097e9019 dashboard link: https://syzkaller.appspot.com/bug?extid=8c91f5d054e998721c57 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11d54c02100000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17461e06100000 The bug was bisected to: commit b41e98524e424d104aa7851d54fd65820759875a Author: Jens Axboe <axboe@xxxxxxxxx> Date: Mon Feb 17 16:52:41 2020 +0000 io_uring: add per-task callback handler bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1488dc3c100000 final crash: https://syzkaller.appspot.com/x/report.txt?x=1688dc3c100000 console output: https://syzkaller.appspot.com/x/log.txt?x=1288dc3c100000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+8c91f5d054e998721c57@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: b41e98524e42 ("io_uring: add per-task callback handler") RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319 RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260 R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000 INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 7090 Comm: syz-executor222 Not tainted 5.7.0-rc1-next-20200415-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+0x104/0x4c50 kernel/locking/lockdep.c:4234 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:122 io_cqring_ev_posted+0xa5/0x1e0 fs/io_uring.c:1160 io_poll_remove_all fs/io_uring.c:4357 [inline] io_ring_ctx_wait_and_kill+0x2bc/0x5a0 fs/io_uring.c:7305 io_uring_create fs/io_uring.c:7843 [inline] io_uring_setup+0x115e/0x22b0 fs/io_uring.c:7870 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x441319 Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319 RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260 R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000 general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 7090 Comm: syz-executor222 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:232 [inline] RIP: 0010:__wake_up_common+0xdc/0x600 kernel/sched/wait.c:86 Code: b9 04 00 00 4c 8b 43 40 49 83 e8 18 49 8d 78 18 48 39 fd 0f 84 d0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 e3 04 00 00 49 bd 00 00 00 00 00 fc ff df 4d 8b RSP: 0018:ffffc90001677c20 EFLAGS: 00010046 RAX: dffffc0000000000 RBX: ffff8880a6081120 RCX: 1ffffffff1517002 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000 RBP: ffff8880a6081160 R08: ffffffffffffffe8 R09: ffffc90001677cb8 R10: 0000000000000003 R11: fffff520002cef7e R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 FS: 000000000136f880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000140 CR3: 00000000936b4000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:123 io_cqring_ev_posted+0xa5/0x1e0 fs/io_uring.c:1160 io_poll_remove_all fs/io_uring.c:4357 [inline] io_ring_ctx_wait_and_kill+0x2bc/0x5a0 fs/io_uring.c:7305 io_uring_create fs/io_uring.c:7843 [inline] io_uring_setup+0x115e/0x22b0 fs/io_uring.c:7870 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x441319 Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffb1fb9aa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319 RDX: 0000000000000001 RSI: 0000000020000140 RDI: 000000000000047b RBP: 0000000000010475 R08: 0000000000000001 R09: 00000000004002c8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402260 R13: 00000000004022f0 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace bf24b131500537a6 ]--- RIP: 0010:__read_once_size include/linux/compiler.h:232 [inline] RIP: 0010:__wake_up_common+0xdc/0x600 kernel/sched/wait.c:86 Code: b9 04 00 00 4c 8b 43 40 49 83 e8 18 49 8d 78 18 48 39 fd 0f 84 d0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 e3 04 00 00 49 bd 00 00 00 00 00 fc ff df 4d 8b RSP: 0018:ffffc90001677c20 EFLAGS: 00010046 RAX: dffffc0000000000 RBX: ffff8880a6081120 RCX: 1ffffffff1517002 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000 RBP: ffff8880a6081160 R08: ffffffffffffffe8 R09: ffffc90001677cb8 R10: 0000000000000003 R11: fffff520002cef7e R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 FS: 000000000136f880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000140 CR3: 00000000936b4000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- 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