syzbot

FS-Cache: O-cookie d=00000000cef4107f n=000000000040a2d4
FS-Cache: O-key=[10] '34323934393830363032'
FS-Cache: N-cookie c=0000000030717d76 [p=00000000b4187b5a fl=2 nc=0 na=1]
FS-Cache: N-cookie d=00000000cef4107f n=000000004e4909b0
FS-Cache: N-key=[10] '34323934393830363032'
INFO: task syz-executor3:8041 blocked for more than 140 seconds.
      Not tainted 5.0.0-rc3+ #44
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D25224  8041   8003 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x897/0x1e60 kernel/sched/core.c:3472
 schedule+0xfe/0x350 kernel/sched/core.c:3516
 schedule_timeout+0x1d3/0x250 kernel/time/timer.c:1779
 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+0x457/0x810 kernel/sched/completion.c:136
 __flush_work+0x5af/0xa20 kernel/workqueue.c:2917
 __cancel_work_timer+0x48d/0x810 kernel/workqueue.c:3004
 cancel_work_sync+0x18/0x20 kernel/workqueue.c:3040
 p9_conn_destroy net/9p/trans_fd.c:883 [inline]
 p9_fd_close+0x405/0x720 net/9p/trans_fd.c:913
 p9_client_destroy+0xce/0x400 net/9p/client.c:1100
 v9fs_session_close+0x99/0x440 fs/9p/v9fs.c:513
 v9fs_kill_super+0x4e/0xa0 fs/9p/vfs_super.c:233
 deactivate_locked_super+0x9a/0x100 fs/super.c:330
 v9fs_mount+0x658/0x920 fs/9p/vfs_super.c:214
 mount_fs+0x123/0x43a fs/super.c:1258
 vfs_kern_mount.part.0+0xdb/0x570 fs/namespace.c:959
 vfs_kern_mount fs/namespace.c:949 [inline]
 do_new_mount fs/namespace.c:2513 [inline]
 do_mount+0x58e/0x3330 fs/namespace.c:2847
 ksys_mount+0xdb/0x150 fs/namespace.c:3063
 __do_sys_mount fs/namespace.c:3077 [inline]
 __se_sys_mount fs/namespace.c:3074 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3074
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 <c6> 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7
RSP: 002b:00007f4b383bcc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000458099
RDX: 00000000200003c0 RSI: 0000000020000380 RDI: 0000000000000000
RBP: 000000000073bf00 R08: 00000000200004c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4b383bd6d4
R13: 00000000004c3e31 R14: 00000000004d6ee8 R15: 00000000ffffffff
INFO: task syz-executor5:8045 blocked for more than 140 seconds.
      Not tainted 5.0.0-rc3+ #44
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D25528  8045   8009 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x897/0x1e60 kernel/sched/core.c:3472
 schedule+0xfe/0x350 kernel/sched/core.c:3516
 schedule_timeout+0x1d3/0x250 kernel/time/timer.c:1779
 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+0x457/0x810 kernel/sched/completion.c:136
 __flush_work+0x5af/0xa20 kernel/workqueue.c:2917
 __cancel_work_timer+0x48d/0x810 kernel/workqueue.c:3004
 cancel_work_sync+0x18/0x20 kernel/workqueue.c:3040
 p9_conn_destroy net/9p/trans_fd.c:883 [inline]
 p9_fd_close+0x405/0x720 net/9p/trans_fd.c:913
 p9_client_destroy+0xce/0x400 net/9p/client.c:1100
 v9fs_session_close+0x99/0x440 fs/9p/v9fs.c:513
 v9fs_kill_super+0x4e/0xa0 fs/9p/vfs_super.c:233
 deactivate_locked_super+0x9a/0x100 fs/super.c:330
 v9fs_mount+0x658/0x920 fs/9p/vfs_super.c:214
 mount_fs+0x123/0x43a fs/super.c:1258
 vfs_kern_mount.part.0+0xdb/0x570 fs/namespace.c:959
 vfs_kern_mount fs/namespace.c:949 [inline]
 do_new_mount fs/namespace.c:2513 [inline]
 do_mount+0x58e/0x3330 fs/namespace.c:2847
 ksys_mount+0xdb/0x150 fs/namespace.c:3063
 __do_sys_mount fs/namespace.c:3077 [inline]
 __se_sys_mount fs/namespace.c:3074 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3074
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 <c6> 10 0f 11 07 48 83 c7 10 0f 10 06 48 83 c6 10 0f 11 07 48 83 c7
RSP: 002b:00007fedc3a17c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000458099
RDX: 00000000200003c0 RSI: 0000000020000380 RDI: 0000000000000000
RBP: 000000000073bf00 R08: 00000000200004c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fedc3a186d4
R13: 00000000004c3e31 R14: 00000000004d6ee8 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1040:
 #0: 0000000041cdfb64 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4389
1 lock held by rsyslogd/7872:
 #0: 00000000e6d564a7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:795
2 locks held by getty/7962:
 #0: 0000000037797f1e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000006398c57d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154
2 locks held by getty/7963:
 #0: 00000000000738f0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000bfeb3234 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154
2 locks held by getty/7964:
 #0: 0000000035f63249 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 0000000036ee1d0c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154
2 locks held by getty/7965:
 #0: 00000000965d0b8e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000e9741eca (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154
2 locks held by getty/7966:
 #0: 0000000075b2bc01 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000f8b82895 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154
2 locks held by getty/7967:
 #0: 00000000acad4d87 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 0000000058ce2490 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154
2 locks held by getty/7968:
 #0: 000000001b335547 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000e04de11d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154
2 locks held by kworker/1:3/8025:
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124
 #1: 000000003d0fbacf ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128
2 locks held by kworker/1:4/8028:
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000b728e8f7 ((wq_completion)"events"){+.+.}, at: process_one_work+0xbc7/0x1ce0 kernel/workqueue.c:2124
 #1: 00000000324b7b05 ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0xc1d/0x1ce0 kernel/workqueue.c:2128

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc3+ #44
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+0x1db/0x2d0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 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+0xbbb/0x1170 kernel/hung_task.c:287
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8026 Comm: kworker/u4:3 Not tainted 5.0.0-rc3+ #44
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
RIP: 0010:batadv_nc_worker+0x356/0x920 net/batman-adv/network-coding.c:730
Code: 8b 85 f8 fe ff ff 48 c1 e8 03 42 0f b6 04 38 84 c0 74 08 3c 03 0f 8e 16 05 00 00 44 8b 63 10 44 89 f7 44 89 e6 e8 0a ab ae f9 <45> 39 e6 0f 82 f1 fd ff ff 4c 8b b5 e8 fe ff ff e8 f5 a9 ae f9 4d
RSP: 0018:ffff88809673f8b8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff888098fc2100 RCX: ffffffff87d356c6
RDX: 0000000000000400 RSI: 00000000000003f4 RDI: 0000000000000004
RBP: ffff88809673f9e0 R08: ffff88808eb643c0 R09: 0000000000000003
R10: 0000000000000000 R11: ffff8880ae72dc7b R12: 0000000000000400
R13: 0000000000000000 R14: 00000000000003f4 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e722e6140 CR3: 000000009483b000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153
 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352