INFO: task syz-executor.3:11135 blocked for more than 140 seconds. Not tainted 4.14.296-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27192 11135 7986 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 flush_work+0x3fe/0x770 kernel/workqueue.c:2894 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2965 p9_conn_destroy net/9p/trans_fd.c:898 [inline] p9_fd_close+0x28d/0x420 net/9p/trans_fd.c:925 p9_client_create+0x736/0x12c0 net/9p/client.c:1093 v9fs_session_init+0x1c5/0x1540 fs/9p/v9fs.c:422 v9fs_mount+0x73/0x860 fs/9p/vfs_super.c:135 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] do_mount+0xe65/0x2a30 fs/namespace.c:2905 SYSC_mount fs/namespace.c:3121 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3098 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fb26022a5a9 RSP: 002b:00007fb25e75b168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fb26034b120 RCX: 00007fb26022a5a9 RDX: 0000000020000080 RSI: 0000000020000300 RDI: 0000000000000000 RBP: 00007fb2602857b0 R08: 0000000020000740 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe3139fb1f R14: 00007fb25e75b300 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/u4:0/5: #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x110/0x840 net/core/net_namespace.c:453 1 lock held by khungtaskd/1513: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by kworker/0:3/8581: #0: ("events"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((&m->rq)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1513 Comm: khungtaskd Not tainted 4.14.296-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18138 Comm: syz-executor.5 Not tainted 4.14.296-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 task: ffff88809acee080 task.stack: ffff8880718a8000 RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:100 RSP: 0018:ffff8880ba407eb8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff88cca000 RCX: 0000000000000020 RDX: 1ffffffff119941d RSI: 000000000000003e RDI: 0000000000000380 RBP: ffff8880ba4282c0 R08: ffff88823fff7018 R09: ffff88823fff700f R10: ffff88823fff7017 R11: 00000044965fafa9 R12: 000000000000003e R13: 0000000000000003 R14: 000000434882737f R15: 68de5d5264d055c5 FS: 00007f5c6acd5700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa37f51a000 CR3: 000000009a1e4000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:385 [inline] lapic_next_event+0x53/0x80 arch/x86/kernel/apic/apic.c:468 clockevents_program_event+0x1f1/0x2d0 kernel/time/clockevents.c:339 tick_program_event+0x78/0xd0 kernel/time/tick-oneshot.c:47 hrtimer_interrupt+0x336/0x5e0 kernel/time/hrtimer.c:1334 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1104 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:do_filp_open+0x2f/0x3c0 fs/namei.c:3599 RSP: 0018:ffff8880718afcd8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10 RAX: ffff8880718afcd8 RBX: 0000000000000000 RCX: ffffc900088f8000 RDX: ffff8880718afe88 RSI: ffff8880b4e889c0 RDI: 00000000ffffff9c RBP: ffff8880b4e889c0 R08: ffffffff8b9be5e8 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88809acee080 R12: 00000000ffffff9c R13: ffff8880718afe88 R14: dffffc0000000000 R15: 00007f5c6acd50d0 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f5c6c714654 RSP: 002b:00007f5c6acd5040 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f5c6c882f80 RCX: 00007f5c6c714654 RDX: 0000000000000000 RSI: 00007f5c6acd50d0 RDI: 00000000ffffff9c RBP: 00007f5c6acd50d0 R08: 0000000000000000 R09: 00007f5c6acd4f50 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fff7340681f R14: 00007f5c6acd5300 R15: 0000000000022000 Code: 83 3d 3c e3 0b 0a 01 7f 02 5d c3 89 ef 5d e9 5f 67 df 05 48 c7 c7 00 74 2e 8b e8 34 74 5c 00 eb df 66 90 89 ff 89 b7 00 c0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb