syzbot


INFO: task hung in ip6gre_exit_net

Status: auto-closed as invalid on 2020/11/07 21:06
Reported-by: syzbot+2ec77a98bfe0e869dae4@syzkaller.appspotmail.com
First crash: 1702d, last: 1596d

Sample crash report:
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
INFO: task kworker/u4:4:2334 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:4    D27232  2334      2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ip6gre_exit_net+0x70/0x580 net/ipv6/ip6_gre.c:1206
 ops_exit_list.isra.0+0x9d/0x140 net/core/net_namespace.c:142
 cleanup_net+0x3bb/0x820 net/core/net_namespace.c:484
 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task kworker/1:2:3333 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:2     D27360  3333      2 0x80000000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 reg_check_chans_work+0x65/0xcc0 net/wireless/reg.c:1655
 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task kworker/1:3:7292 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:3     D26656  7292      2 0x80000000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150
 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task syz-executor.3:9676 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28816  9676   6346 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
 inet_ioctl+0xf6/0x190 net/ipv4/af_inet.c:900
 packet_ioctl+0xab/0x280 net/packet/af_packet.c:4175
 sock_do_ioctl+0x5f/0xa0 net/socket.c:974
 sock_ioctl+0x28d/0x450 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007fa7abda4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f54c0 RCX: 000000000045cba9
RDX: 0000000020000080 RSI: 0000000000008914 RDI: 0000000000000004
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006df R14: 00000000004c9d8d R15: 00007fa7abda56d4
INFO: task syz-executor.3:9686 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D30144  9686   6346 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
 inet_ioctl+0xf6/0x190 net/ipv4/af_inet.c:900
 packet_ioctl+0xab/0x280 net/packet/af_packet.c:4175
 sock_do_ioctl+0x5f/0xa0 net/socket.c:974
 sock_ioctl+0x28d/0x450 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007fa7abd83c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f54c0 RCX: 000000000045cba9
RDX: 0000000020000100 RSI: 0000000000008914 RDI: 0000000000000004
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006df R14: 00000000004c9d8d R15: 00007fa7abd846d4
INFO: task syz-executor.0:9672 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28816  9672   6343 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
 inet_ioctl+0xf6/0x190 net/ipv4/af_inet.c:900
 packet_ioctl+0xab/0x280 net/packet/af_packet.c:4175
 sock_do_ioctl+0x5f/0xa0 net/socket.c:974
 sock_ioctl+0x28d/0x450 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f7d18fb3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f54c0 RCX: 000000000045cba9
RDX: 0000000020000080 RSI: 0000000000008914 RDI: 0000000000000004
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006df R14: 00000000004c9d8d R15: 00007f7d18fb46d4
INFO: task syz-executor.0:9681 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29408  9681   6343 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 exp_funnel_lock kernel/rcu/tree_exp.h:295 [inline]
 _synchronize_rcu_expedited+0x669/0x820 kernel/rcu/tree_exp.h:596
 synchronize_net+0x2b/0x40 net/core/dev.c:8236
 dev_deactivate_many+0x3cf/0x980 net/sched/sch_generic.c:935
 __dev_close_many+0x102/0x250 net/core/dev.c:1441
 __dev_close net/core/dev.c:1466 [inline]
 __dev_change_flags+0x205/0x510 net/core/dev.c:6795
 dev_change_flags+0x7e/0x130 net/core/dev.c:6863
 devinet_ioctl+0xee6/0x1580 net/ipv4/devinet.c:1089
 inet_ioctl+0xf6/0x190 net/ipv4/af_inet.c:900
 packet_ioctl+0xab/0x280 net/packet/af_packet.c:4175
 sock_do_ioctl+0x5f/0xa0 net/socket.c:974
 sock_ioctl+0x28d/0x450 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f7d18f92c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f54c0 RCX: 000000000045cba9
RDX: 0000000020000100 RSI: 0000000000008914 RDI: 0000000000000004
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006df R14: 00000000004c9d8d R15: 00007f7d18f936d4
INFO: task syz-executor.1:9677 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28032  9677   6347 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ip6_mroute_setsockopt+0x95b/0x2780 net/ipv6/ip6mr.c:1706
 do_ipv6_setsockopt.isra.0+0x325/0x3710 net/ipv6/ipv6_sockglue.c:163
 ipv6_setsockopt+0xcc/0x130 net/ipv6/ipv6_sockglue.c:930
 rawv6_setsockopt+0x46/0x100 net/ipv6/raw.c:1083
 SYSC_setsockopt net/socket.c:1865 [inline]
 SyS_setsockopt+0x110/0x1e0 net/socket.c:1844
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f08ad736c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000505cc0 RCX: 000000000045cba9
RDX: 00000000000000ca RSI: 0000000000000029 RDI: 0000000000000006
RBP: 000000000078bf00 R08: 000000000000000c R09: 0000000000000000
R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000aff R14: 00000000004cdcb6 R15: 00007f08ad7376d4
INFO: task syz-executor.2:9695 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D30096  9695   6344 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 dev_ioctl+0x27c/0xcb0 net/core/dev_ioctl.c:421
 sock_do_ioctl+0x8c/0xa0 net/socket.c:981
 sock_ioctl+0x28d/0x450 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f5fc331cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004ea600 RCX: 000000000045cba9
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000424 R14: 00000000004c7009 R15: 00007f5fc331d6d4
INFO: task syz-executor.2:9701 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D30144  9701   6344 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
 inet_ioctl+0xf6/0x190 net/ipv4/af_inet.c:900
 packet_ioctl+0xab/0x280 net/packet/af_packet.c:4175
 sock_do_ioctl+0x5f/0xa0 net/socket.c:974
 sock_ioctl+0x28d/0x450 net/socket.c:1071
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f5fc32fbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f54c0 RCX: 000000000045cba9
RDX: 0000000020000100 RSI: 0000000000008914 RDI: 0000000000000004
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006df R14: 00000000004c9d8d R15: 00007f5fc32fc6d4

Showing all locks held in the system:
3 locks held by kworker/0:0/3:
 #0:  ("%s"("ipv6_addrconf")){+.+.}, at: [<ffffffff813af918>] process_one_work+0x6d8/0x14c0 kernel/workqueue.c:2087
 #1:  ((addr_chk_work).work){+.+.}, at: [<ffffffff813af94e>] process_one_work+0x70e/0x14c0 kernel/workqueue.c:2091
 #2:  (rtnl_mutex){+.+.}, at: [<ffffffff8570002a>] addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4412
1 lock held by khungtaskd/1057:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff8146c8d0>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
4 locks held by kworker/u4:4/2334:
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff813af918>] process_one_work+0x6d8/0x14c0 kernel/workqueue.c:2087
 #1:  (net_cleanup_work){+.+.}, at: [<ffffffff813af94e>] process_one_work+0x70e/0x14c0 kernel/workqueue.c:2091
 #2:  (net_mutex){+.+.}, at: [<ffffffff84fc1d73>] cleanup_net+0x123/0x820 net/core/net_namespace.c:450
 #3:  (rtnl_mutex){+.+.}, at: [<ffffffff85841be0>] ip6gre_exit_net+0x70/0x580 net/ipv6/ip6_gre.c:1206
3 locks held by kworker/1:2/3333:
 #0:  ("events_power_efficient"){+.+.}, at: [<ffffffff813af918>] process_one_work+0x6d8/0x14c0 kernel/workqueue.c:2087
 #1:  ((reg_check_chans).work){+.+.}, at: [<ffffffff813af94e>] process_one_work+0x70e/0x14c0 kernel/workqueue.c:2091
 #2:  (rtnl_mutex){+.+.}, at: [<ffffffff85d88845>] reg_check_chans_work+0x65/0xcc0 net/wireless/reg.c:1655
1 lock held by systemd-journal/3627:
 #0:  (&rq->lock){-.-.}, at: [<ffffffff81428fa4>] idle_balance kernel/sched/fair.c:8462 [inline]
 #0:  (&rq->lock){-.-.}, at: [<ffffffff81428fa4>] pick_next_task_fair+0xab4/0x1340 kernel/sched/fair.c:6378
3 locks held by kworker/1:3/7292:
 #0:  ("events"){+.+.}, at: [<ffffffff813af918>] process_one_work+0x6d8/0x14c0 kernel/workqueue.c:2087
 #1:  (deferred_process_work){+.+.}, at: [<ffffffff813af94e>] process_one_work+0x70e/0x14c0 kernel/workqueue.c:2091
 #2:  (rtnl_mutex){+.+.}, at: [<ffffffff86368ada>] switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150
1 lock held by syz-executor.3/9676:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8555cce6>] devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
1 lock held by syz-executor.3/9686:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8555cce6>] devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
1 lock held by syz-executor.0/9672:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8555cce6>] devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
1 lock held by syz-executor.0/9681:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8555cce6>] devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
1 lock held by syz-executor.1/9677:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff857b77fb>] ip6_mroute_setsockopt+0x95b/0x2780 net/ipv6/ip6mr.c:1706
1 lock held by syz-executor.2/9695:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8504ef8c>] dev_ioctl+0x27c/0xcb0 net/core/dev_ioctl.c:421
1 lock held by syz-executor.2/9701:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8555cce6>] devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020
1 lock held by syz-executor.2/9705:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff8555cce6>] devinet_ioctl+0x166/0x1580 net/ipv4/devinet.c:1020

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

NMI backtrace for cpu 0
CPU: 0 PID: 1057 Comm: khungtaskd Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x17f 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+0x5e2/0xb80 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3627 Comm: systemd-journal Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880944fc400 task.stack: ffff888094500000
RIP: 0010:in_task_stack+0x19/0x40 arch/x86/kernel/dumpstack.c:45
RSP: 0018:ffff888094507a78 EFLAGS: 00000212
RAX: ffff888094500000 RBX: ffff888094507b40 RCX: ffff888094508000
RDX: ffff888094507b40 RSI: ffff8880944fc400 RDI: ffff888094507aa8
RBP: ffff888094507aa8 R08: 0000000000000001 R09: ffff888094507b68
R10: ffffed10128a0f72 R11: ffff888094507b97 R12: ffff8880944fc400
R13: ffff888094507b60 R14: dffffc0000000000 R15: ffff888094507b40
FS:  00007f1c3f4538c0(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1c3c866000 CR3: 0000000094b5f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 get_stack_info+0x32/0x140 arch/x86/kernel/dumpstack_64.c:115
 __unwind_start arch/x86/kernel/unwind_orc.c:555 [inline]
 __unwind_start+0x4bf/0x8c0 arch/x86/kernel/unwind_orc.c:512
 unwind_start arch/x86/include/asm/unwind.h:60 [inline]
 __save_stack_trace+0x4a/0xd0 arch/x86/kernel/stacktrace.c:43
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551
 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
 getname_flags+0xc8/0x550 fs/namei.c:138
 getname fs/namei.c:209 [inline]
 user_path_create fs/namei.c:3732 [inline]
 SYSC_mkdirat fs/namei.c:3864 [inline]
 SyS_mkdirat+0x83/0x220 fs/namei.c:3856
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f1c3e70f687
RSP: 002b:00007ffd3fda4468 EFLAGS: 00000293 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007ffd3fda7380 RCX: 00007f1c3e70f687
RDX: 00007f1c3f180a00 RSI: 00000000000001ed RDI: 000055eca07778c0
RBP: 00007ffd3fda44a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffd3fda7380 R15: 00007ffd3fda4990
Code: eb ae 0f 0b 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 48 8b 46 18 48 8d 88 00 80 00 00 48 39 f8 77 21 48 39 f9 76 1c 48 89 42 08 <b8> 01 00 00 00 c7 02 01 00 00 00 48 89 4a 10 48 c7 42 18 00 00 

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/07/10 21:05 linux-4.14.y b850307b279c 18d18b59 .config console log report ci2-linux-4-14
2020/03/27 05:16 linux-4.14.y 01364dad1d45 6d25c5a0 .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.