INFO: task syz-executor.0:9264 blocked for more than 140 seconds. Not tainted 4.19.62 #36 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27576 9264 7843 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1780 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __flush_work+0x49f/0x870 kernel/workqueue.c:2920 __cancel_work_timer+0x3bf/0x520 kernel/workqueue.c:3007 cancel_work_sync+0x18/0x20 kernel/workqueue.c:3043 p9_conn_destroy net/9p/trans_fd.c:883 [inline] p9_fd_close+0x329/0x570 net/9p/trans_fd.c:913 p9_client_destroy+0xc9/0x360 net/9p/client.c:1100 v9fs_session_close+0x4a/0x2d0 fs/9p/v9fs.c:513 v9fs_kill_super+0x4e/0xa0 fs/9p/vfs_super.c:233 deactivate_locked_super+0x95/0x100 fs/super.c:329 v9fs_mount+0x65a/0x920 fs/9p/vfs_super.c:214 mount_fs+0xa8/0x31f fs/super.c:1261 vfs_kern_mount.part.0+0x6f/0x410 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x53e/0x2bc0 fs/namespace.c:2799 ksys_mount+0xdb/0x150 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3026 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: ff ff c3 c5 f8 77 eb 60 80 3d 3c e4 37 01 01 0f 85 7f fd ff ff 48 83 f8 0c 0f 83 74 fe ff ff 48 8d 75 10 66 f7 c6 f0 0f 0f 84 <66> fd ff ff f3 0f 6f 4d 00 48 8d 74 17 f1 49 c7 c1 10 00 00 00 49 RSP: 002b:00007fd46f472c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459829 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 000000000075bfc8 R08: 0000000020001280 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd46f4736d4 R13: 00000000004c5dcf R14: 00000000004da7d0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1040: #0: 00000000446d90d1 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/7677: #0: 00000000b2c817d7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7799: #0: 000000007bd19923 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000098b52249 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7800: #0: 0000000020a96a51 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000067911963 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7801: #0: 000000007e86c51b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000098c7942 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7802: #0: 000000007cca73da (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000006926cd0b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7803: #0: 000000001d79d26f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000991bfebc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7804: #0: 000000004c591107 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000051641f95 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7805: #0: 000000005676f8a9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000023460f3a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by kworker/1:2/32677: #0: 00000000a5cfe5e2 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000a5cfe5e2 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000a5cfe5e2 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000a5cfe5e2 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000a5cfe5e2 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000a5cfe5e2 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000a5cfe5e2 ((wq_completion)"events"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 0000000050eab12f ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 4.19.62 #36 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 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: 100 Comm: kworker/u4:3 Not tainted 4.19.62 #36 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:strscpy+0x84/0x280 lib/string.c:206 Code: 03 80 3c 11 00 0f 85 95 01 00 00 4b 89 04 37 48 8b 45 d0 49 83 c6 08 4c 89 e9 4c 29 f1 4c 29 f0 48 83 f8 07 0f 86 ac 00 00 00 <4a> 8d 3c 33 e8 53 ff ff ff 4b 8d 3c 37 48 ba 80 80 80 80 80 80 80 RSP: 0018:ffff8880a9b57cf0 EFLAGS: 00000046 RAX: ffff88821603e580 RBX: ffff88821603e6b0 RCX: 0000000000000000 RDX: 0000000000000018 RSI: ffff88821603e6b0 RDI: ffff8880a9951b68 RBP: ffff8880a9b57d30 R08: ffff8880a9b483c0 R09: fffffbfff1493e62 R10: fffffbfff1493e61 R11: ffffffff8a49f30b R12: fefefefefefefeff R13: 0000000000000018 R14: 0000000000000000 R15: ffff8880a9951b68 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c420b56d48 CR3: 0000000093504000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0x59d/0x1750 kernel/workqueue.c:2095 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415