INFO: task syz-executor.4:10841 blocked for more than 143 seconds. Not tainted 5.11.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27744 pid:10841 ppid: 8496 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5064 schedule+0xcf/0x270 kernel/sched/core.c:5143 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 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 __flush_work+0x51f/0xac0 kernel/workqueue.c:3052 __cancel_work_timer+0x3b3/0x520 kernel/workqueue.c:3139 p9_conn_destroy net/9p/trans_fd.c:891 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:921 p9_client_destroy+0xbe/0x360 net/9p/client.c:1088 v9fs_session_init+0xfd2/0x1770 fs/9p/v9fs.c:482 v9fs_mount+0x79/0x9c0 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1496 do_new_mount fs/namespace.c:2878 [inline] path_mount+0x13ad/0x20c0 fs/namespace.c:3208 do_mount fs/namespace.c:3221 [inline] __do_sys_mount fs/namespace.c:3429 [inline] __se_sys_mount fs/namespace.c:3406 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3406 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 RSP: 002b:00007f9542665c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000119c078 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffe00fd5eef R14: 00007f95426669c0 R15: 000000000119c034 Showing all locks held in the system: 1 lock held by khungtaskd/1649: #0: ffffffff8b373920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8364: #0: ffff888022b16170 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 2 locks held by kworker/1:1/8650: #0: ffff888010063d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010063d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90002067da8 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1649 Comm: khungtaskd Not tainted 5.11.0-rc3-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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8365 Comm: rs:main Q:Reg Not tainted 5.11.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_preemption_disabled+0x4/0x150 lib/smp_processor_id.c:13 Code: 8b 1d 68 7a 09 04 31 ff 89 de 0f 1f 44 00 00 85 db 75 ae 0f 1f 44 00 00 41 bc 01 00 00 00 e8 53 60 c2 fa eb 9f cc 41 56 41 55 <49> 89 f5 41 54 55 48 89 fd 53 0f 1f 44 00 00 65 44 8b 25 b5 3b 07 RSP: 0018:ffffc9000c18f850 EFLAGS: 00000046 RAX: 0000000000000003 RBX: 9a5ecc8aff99ba9a RCX: ffffc9000c18f8b8 RDX: 1ffff1100321f58f RSI: ffffffff894bab80 RDI: ffffffff899e8020 RBP: 1ffff92001831f0f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000004 R14: ffff8880190fac80 R15: ffff8880190fa300 FS: 00007f3c01087700(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdb3449d000 CR3: 0000000027d32000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:437 [inline] lock_release+0x3bb/0x710 kernel/locking/lockdep.c:5459 mark_buffer_dirty+0x450/0x5d0 fs/buffer.c:1139 __block_commit_write.constprop.0.isra.0+0x222/0x360 fs/buffer.c:2084 block_write_end fs/buffer.c:2162 [inline] generic_write_end+0xc9/0x4f0 fs/buffer.c:2176 ext4_da_write_end+0x20f/0xb50 fs/ext4/inode.c:3111 generic_perform_write+0x2c0/0x4f0 mm/filemap.c:3419 ext4_buffered_write_iter+0x244/0x4d0 fs/ext4/file.c:270 ext4_file_write_iter+0x423/0x14d0 fs/ext4/file.c:664 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x791/0xa30 fs/read_write.c:605 ksys_write+0x12d/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f3c03acb1cd 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:00007f3c01086590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3bf8025cf0 RCX: 00007f3c03acb1cd RDX: 000000000000052b RSI: 00007f3bf8025cf0 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f3bf8025a70 R13: 00007f3c010865b0 R14: 000055d443ae9360 R15: 000000000000052b