INFO: task syz-executor.3:17418 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28416 17418 8121 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 __flush_work+0x4bb/0x8b0 kernel/workqueue.c:2926 __cancel_work_timer+0x412/0x590 kernel/workqueue.c:3013 p9_conn_destroy net/9p/trans_fd.c:904 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:934 p9_client_create+0x901/0x12e0 net/9p/client.c:1084 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:421 v9fs_mount+0x73/0x910 fs/9p/vfs_super.c:135 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fcb2f1e60f9 Code: Bad RIP value. RSP: 002b:00007fcb2d716168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fcb2f306120 RCX: 00007fcb2f1e60f9 RDX: 0000000020000500 RSI: 00000000200004c0 RDI: 0000000000000000 RBP: 00007fcb2f241ae9 R08: 0000000020000540 R09: 0000000000000000 R10: 0000000002000006 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce3fa5a1f R14: 00007fcb2d716300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 000000004fe9bdaf (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7798: #0: 00000000d4aa8f74 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 3 locks held by kworker/u4:5/8885: 2 locks held by kworker/1:1/32660: #0: 0000000081f1c02d ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000e8e8ebc7 ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 3 locks held by kworker/u4:12/20022: #0: 00000000d6fba8db ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000f007fa6c (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000f5891d1a (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 3 locks held by syz-executor.4/28845: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4691 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 RIP: 0010:__write_once_size include/linux/compiler.h:289 [inline] RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:103 [inline] RIP: 0010:do_raw_spin_unlock+0x124/0x230 kernel/locking/spinlock_debug.c:134 Code: c1 ea 03 80 3c 02 00 0f 85 f5 00 00 00 4c 89 e2 48 c7 45 10 ff ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 <4c> 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 92 00 00 00 48 RSP: 0018:ffff8880a0d07d10 EFLAGS: 00000802 RAX: dffffc0000000000 RBX: 0000000000000286 RCX: ffffffff814be140 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8d40b488 RBP: ffffffff8d40b488 R08: 0000000000000000 R09: fffffbfff1a81691 R10: ffffffff8d40b48b R11: 0000000000000000 R12: ffffffff8d40b490 R13: ffffffff8d40b498 R14: ffffffff8d40b488 R15: ffff8880b2ff7840 FS: 00007f348b4db8c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002080007f CR3: 00000000a0d2f000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irqrestore+0x23/0xe0 kernel/locking/spinlock.c:184 debug_object_active_state lib/debugobjects.c:749 [inline] debug_object_active_state+0x254/0x330 lib/debugobjects.c:713 debug_rcu_head_queue kernel/rcu/rcu.h:194 [inline] __call_rcu.constprop.0+0x4a/0x7f0 kernel/rcu/tree.c:2977 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f348aa6a840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007fff4da06808 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: fffffffffffffffe RBX: 00007fff4da06b10 RCX: 00007f348aa6a840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000559b770a2bd0 RBP: 000000000000000d R08: 00000000000001e0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000559b77096040 R14: 00007fff4da06ad0 R15: 0000559b770a29f0