INFO: task syz-executor455:6861 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200903-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor455 state:D stack:28104 pid: 6861 ppid: 6855 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3777 [inline] __schedule+0xea9/0x2230 kernel/sched/core.c:4526 schedule+0xd0/0x2a0 kernel/sched/core.c:4601 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 io_sq_thread_stop fs/io_uring.c:6906 [inline] io_finish_async fs/io_uring.c:6920 [inline] io_sq_offload_create fs/io_uring.c:7595 [inline] io_uring_create fs/io_uring.c:8671 [inline] io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440229 Code: Bad RIP value. RSP: 002b:00007ffe81fac3a8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440229 RDX: 0000000000400ad0 RSI: 0000000020000140 RDI: 00000000000062c6 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401a30 R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000 INFO: task io_uring-sq:6862 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200903-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:io_uring-sq state:D stack:31200 pid: 6862 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3777 [inline] __schedule+0xea9/0x2230 kernel/sched/core.c:4526 schedule+0xd0/0x2a0 kernel/sched/core.c:4601 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660 kthread+0x2ac/0x4a0 kernel/kthread.c:285 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Showing all locks held in the system: 1 lock held by khungtaskd/1169: #0: ffffffff89c67500 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 1 lock held by in:imklog/6537: #0: ffff8880a5e390f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1169 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200903-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+0x198/0x1fd lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x223 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:339 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6538 Comm: rs:main Q:Reg Not tainted 5.9.0-rc3-next-20200903-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held kernel/locking/lockdep.c:4777 [inline] RIP: 0010:lock_is_held_type+0x5b/0xf0 kernel/locking/lockdep.c:5045 Code: 89 fc 31 db e8 f6 23 60 f9 83 85 0c 09 00 00 01 49 89 c7 8b 85 08 09 00 00 85 c0 7f 0d eb 7d 83 c3 01 3b 9d 08 09 00 00 7d 72 <48> 63 c3 4c 89 e6 48 8d 04 80 4d 8d 74 c5 00 4c 89 f7 e8 4e fc ff RSP: 0018:ffffc90009fd7910 EFLAGS: 00000093 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 1ffffffff130b121 RDX: dffffc0000000000 RSI: ffffffff89c67440 RDI: ffff8880a294aa50 RBP: ffff8880a294a140 R08: 0000000000000000 R09: ffffffff8abcb60f R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89c67440 R13: ffff8880a294aa50 R14: ffff8880a294aa50 R15: 0000000000000286 FS: 00007ff6ed169700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f93960e0028 CR3: 0000000092391000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:267 [inline] rcu_read_lock_sched_held+0x3a/0xb0 kernel/rcu/update.c:123 trace_writeback_mark_inode_dirty include/trace/events/writeback.h:126 [inline] __mark_inode_dirty+0xe05/0x1300 fs/fs-writeback.c:2250 mark_inode_dirty include/linux/fs.h:2179 [inline] generic_write_end+0x316/0x4f0 fs/buffer.c:2239 ext4_da_write_end+0x211/0xbb0 fs/ext4/inode.c:3091 generic_perform_write+0x2c0/0x4f0 mm/filemap.c:3414 ext4_buffered_write_iter+0x235/0x4a0 fs/ext4/file.c:269 ext4_file_write_iter+0x1f0/0x13f0 fs/ext4/file.c:660 call_write_iter include/linux/fs.h:1892 [inline] new_sync_write+0x422/0x650 fs/read_write.c:503 vfs_write+0x5ad/0x730 fs/read_write.c:578 ksys_write+0x12d/0x250 fs/read_write.c:631 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7ff6efbad1cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ff6ed168590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff6e4026010 RCX: 00007ff6efbad1cd RDX: 000000000000044d RSI: 00007ff6e4026010 RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007ff6e4025d90 R13: 00007ff6ed1685b0 R14: 000055b6d78a6440 R15: 000000000000044d