INFO: task syz-executor.0:8853 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28848 pid: 8853 ppid: 8508 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 io_uring_cancel_files fs/io_uring.c:8735 [inline] io_uring_cancel_task_requests fs/io_uring.c:8787 [inline] __io_uring_files_cancel+0xc4d/0x14b0 fs/io_uring.c:8883 io_uring_files_cancel include/linux/io_uring.h:51 [inline] exit_files+0xe4/0x170 fs/file.c:456 do_exit+0xb61/0x29f0 kernel/exit.c:818 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3ea/0x1f70 kernel/signal.c:2750 arch_do_signal_or_restart+0x2a6/0x1ea0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:274 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: Unable to access opcode bytes at RIP 0x45de8f. RSP: 002b:00007f64085e6cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000118bf28 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118bf28 RBP: 000000000118bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fffe17f6c9f R14: 00007f64085e79c0 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1643: #0: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6252 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1643 Comm: khungtaskd Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4884 Comm: systemd-journal Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlock_class kernel/locking/lockdep.c:208 [inline] RIP: 0010:mark_lock+0x105/0x24c0 kernel/locking/lockdep.c:4387 Code: 0f b7 ed be 08 00 00 00 4c 89 e8 48 c1 f8 06 48 8d 3c c5 60 07 bc 8e e8 89 d5 5c 00 4c 0f a3 2d b1 04 66 0d 0f 83 10 01 00 00 <4f> 8d 6c 6d 00 49 c1 e5 06 49 81 c5 80 0b bc 8e 49 8d 7d 50 48 b8 RSP: 0018:ffffc9000159fa20 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 1ffff920002b3f4b RCX: ffffffff815602a7 RDX: fffffbfff1d780f0 RSI: 0000000000000008 RDI: ffffffff8ebc0778 RBP: ffff8880113158a8 R08: 0000000000000000 R09: ffffffff8ebc077f R10: fffffbfff1d780ef R11: 0000000000000000 R12: 0000000000000003 R13: 00000000000000f8 R14: 0000000000000008 R15: 0000000000000000 FS: 00007f348d6ce8c0(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f348aab6000 CR3: 0000000025e08000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4310 [inline] __lock_acquire+0x1216/0x5c00 kernel/locking/lockdep.c:4784 lock_acquire kernel/locking/lockdep.c:5435 [inline] lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5400 __might_fault mm/memory.c:5017 [inline] __might_fault+0x106/0x180 mm/memory.c:5002 strncpy_from_user+0x2f/0x3e0 lib/strncpy_from_user.c:117 getname_flags.part.0+0x95/0x4f0 fs/namei.c:149 getname_flags fs/namei.c:2647 [inline] user_path_at_empty+0xa1/0x100 fs/namei.c:2647 user_path_at include/linux/namei.h:59 [inline] do_faccessat+0x129/0x820 fs/open.c:423 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f348c98a9c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd64acc208 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffd64acf120 RCX: 00007f348c98a9c7 RDX: 00007f348d3fba00 RSI: 0000000000000000 RDI: 000055fa5b21e9a3 RBP: 00007ffd64acc240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffd64acf120 R15: 00007ffd64acc730