INFO: task syz-executor557:6844 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-executor557 state:D stack:28104 pid: 6844 ppid: 6838 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:00007ffea62acfa8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440229 RDX: 0000000000400ad0 RSI: 0000000020000040 RDI: 0000000000007ca3 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401a30 R13: 0000000000401ac0 R14: 0000000000000000 R15: 0000000000000000 INFO: task io_uring-sq:6845 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: 6845 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/6557: #0: ffff8880a164ddb0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6558 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:compound_head include/linux/page-flags.h:182 [inline] RIP: 0010:PageUptodate include/linux/page-flags.h:513 [inline] RIP: 0010:ext4_block_write_begin+0x5f0/0x1410 fs/ext4/inode.c:1076 Code: 0f 85 c3 0c 00 00 4d 8b 24 24 31 ff 49 c1 ec 05 41 83 e4 01 44 89 e6 e8 4e bc 6f ff 45 84 e4 0f 85 ca 07 00 00 e8 00 c0 6f ff <48> 8b 54 24 20 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc90009f27850 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffffffff8205220d RDX: ffff88809e8fc3c0 RSI: ffffffff82052300 RDI: 0000000000000001 RBP: ffffea0002331780 R08: 0000000000000000 R09: ffff88808583c217 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000001000 FS: 00007fd41984a700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd343082000 CR3: 00000000a38a1000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_da_write_begin+0x3e4/0x11d0 fs/ext4/inode.c:2996 generic_perform_write+0x20a/0x4f0 mm/filemap.c:3403 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: 0033:0x7fd41c28e1cd 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:00007fd419849590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd40c0071d0 RCX: 00007fd41c28e1cd RDX: 000000000000044d RSI: 00007fd40c0071d0 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fd40c006f50 R13: 00007fd4198495b0 R14: 000055a376fb5360 R15: 000000000000044d