INFO: task syz-executor.0:28381 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28944 pid:28381 ppid: 8509 flags:0x00004000 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:8720 [inline] io_uring_cancel_task_requests fs/io_uring.c:8772 [inline] __io_uring_files_cancel+0xc4d/0x14b0 fs/io_uring.c:8868 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:00007f32be979cf8 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: 00007fffccbdf20f R14: 00007f32be97a9c0 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1647: #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: 1647 Comm: khungtaskd Not tainted 5.10.0-rc4-next-20201118-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: 4897 Comm: systemd-journal Not tainted 5.10.0-rc4-next-20201118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xd95/0x5c00 kernel/locking/lockdep.c:4700 Code: 01 00 00 00 0f 86 8e 00 00 00 89 05 65 0c 1f 0d e9 83 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 80 3c 02 00 <0f> 85 68 32 00 00 49 81 3e 80 a2 4a 8e 0f 84 3c f3 ff ff 41 83 fc RSP: 0018:ffffc9000168f880 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 1ffffffff1e16f78 RSI: 1ffff920002d1f22 RDI: ffffffff8f0b7bc0 RBP: ffff88801188b500 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8f0b7bc0 R15: 0000000000000000 FS: 00007f2f9444d8c0(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f91835000 CR3: 000000001193b000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5435 [inline] lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5400 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 __debug_check_no_obj_freed lib/debugobjects.c:975 [inline] debug_check_no_obj_freed+0xc7/0x420 lib/debugobjects.c:1018 slab_free_hook mm/slub.c:1537 [inline] slab_free_freelist_hook+0x107/0x150 mm/slub.c:1583 slab_free mm/slub.c:3154 [inline] kmem_cache_free+0x82/0x350 mm/slub.c:3170 putname+0xe1/0x120 fs/namei.c:259 filename_parentat+0x4b1/0x560 fs/namei.c:2418 filename_create+0x9e/0x490 fs/namei.c:3450 user_path_create fs/namei.c:3525 [inline] do_mkdirat+0xa0/0x2d0 fs/namei.c:3665 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f2f93709687 Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffff1808ff8 EFLAGS: 00000293 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffff180bf10 RCX: 00007f2f93709687 RDX: 00007f2f9417aa00 RSI: 00000000000001ed RDI: 000055bccb78d8a0 RBP: 00007ffff1809030 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffff180bf10 R15: 00007ffff1809520