INFO: task hung in cangw_pernet_exit (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=128dbfdab00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=b8e886effece69f5fcc8
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b8e886...@syzkaller.appspotmail.com

Bluetooth: hci3: command 0x0406 tx timeout
ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
INFO: task kworker/u4:2:37 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.
kworker/u4:2 D26136 37 2 0x80000000
Workqueue: netns cleanup_net
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_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
__mutex_lock_common kernel/locking/mutex.c:1016 [inline]
__mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078
cangw_pernet_exit+0xe/0x20 net/can/gw.c:1032
ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153
cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task kworker/0:2:3394 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.
kworker/0:2 D25264 3394 2 0x80000000
Workqueue: events linkwatch_event
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_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
__mutex_lock_common kernel/locking/mutex.c:1016 [inline]
__mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078
linkwatch_event+0xb/0x60 net/core/link_watch.c:236
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task syz-executor.1:8137 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.1 D24184 8137 1 0x80000002
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
flush_all_backlogs net/core/dev.c:5283 [inline]
rollback_registered_many+0x4b1/0xe70 net/core/dev.c:8181
rollback_registered+0xe9/0x1b0 net/core/dev.c:8238
unregister_netdevice_queue+0x1de/0x3e0 net/core/dev.c:9305
unregister_netdevice include/linux/netdevice.h:2615 [inline]
__tun_detach+0x100d/0x1320 drivers/net/tun.c:745
tun_detach drivers/net/tun.c:762 [inline]
tun_chr_close+0xd9/0x180 drivers/net/tun.c:3323
__fput+0x2ce/0x890 fs/file_table.c:278
task_work_run+0x148/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xbf3/0x2be0 kernel/exit.c:870
do_group_exit+0x125/0x310 kernel/exit.c:967
__do_sys_exit_group kernel/exit.c:978 [inline]
__se_sys_exit_group kernel/exit.c:976 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:976
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff884565ae9
Code: Bad RIP value.
RSP: 002b:00007ffd547ade08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000006d RCX: 00007ff884565ae9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043
RBP: 0000000000000000 R08: 0000000000000014 R09: 000000000000006d
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff8845c00c3
R13: 0000000000000000 R14: 0000000000000012 R15: 00007ffd547adff0
INFO: task syz-executor.2:8139 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.2 D24056 8139 1 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_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
__mutex_lock_common kernel/locking/mutex.c:1016 [inline]
__mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078
__blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478
blkdev_get+0xb0/0x940 fs/block_dev.c:1627
blkdev_open+0x202/0x290 fs/block_dev.c:1788
do_dentry_open+0x4aa/0x1160 fs/open.c:796
do_last fs/namei.c:3421 [inline]
path_openat+0x793/0x2df0 fs/namei.c:3537
do_filp_open+0x18c/0x3f0 fs/namei.c:3567
do_sys_open+0x3b3/0x520 fs/open.c:1085
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f2be7d2ba04
Code: Bad RIP value.
RSP: 002b:00007ffe29d30ff0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffe29d310f0 RCX: 00007f2be7d2ba04
RDX: 0000000000000002 RSI: 00007ffe29d31130 RDI: 00000000ffffff9c
RBP: 00007ffe29d31130 R08: 0000000000000000 R09: 00007ffe29d30f00
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000014 R15: 00007ffe29d31130
INFO: task syz-executor.5:8145 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.5 D24216 8145 1 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
lru_add_drain_all+0x374/0x4d0 mm/swap.c:699
invalidate_bdev+0x96/0xd0 fs/block_dev.c:97
ext4_put_super+0x745/0x1010 fs/ext4/super.c:1034
generic_shutdown_super+0x144/0x370 fs/super.c:456
kill_block_super+0x97/0xf0 fs/super.c:1185
deactivate_locked_super+0x94/0x160 fs/super.c:329
deactivate_super+0x174/0x1a0 fs/super.c:360
cleanup_mnt+0x1a8/0x290 fs/namespace.c:1098
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: 0033:0x7f263b2e1f57
Code: Bad RIP value.
RSP: 002b:00007ffe18ca6a98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f263b2e1f57
RDX: 00007ffe18ca6b6a RSI: 000000000000000a RDI: 00007ffe18ca6b60
RBP: 00007ffe18ca6b60 R08: 00000000ffffffff R09: 00007ffe18ca6930
R10: 0000555556783903 R11: 0000000000000246 R12: 00007f263b33a105
R13: 00007ffe18ca7c20 R14: 0000555556783810 R15: 00007ffe18ca7c60
INFO: task syz-executor.3:11394 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 D28280 11394 8141 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_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
__mutex_lock_common kernel/locking/mutex.c:1016 [inline]
__mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078
lru_add_drain_all+0x5a/0x4d0 mm/swap.c:681
invalidate_bdev+0x96/0xd0 fs/block_dev.c:97
__loop_clr_fd+0x479/0xe50 drivers/block/loop.c:1115
loop_clr_fd drivers/block/loop.c:1211 [inline]
lo_ioctl+0x363/0x20e0 drivers/block/loop.c:1580
__blkdev_driver_ioctl block/ioctl.c:303 [inline]
blkdev_ioctl+0x5cb/0x1a80 block/ioctl.c:601
block_ioctl+0xe9/0x130 fs/block_dev.c:1906
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f4c2bc348a7
Code: Bad RIP value.
RSP: 002b:00007f4c29188fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f4c2bc348a7
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000007
RBP: 00007f4c291896bc R08: 00007f4c29189040 R09: 0000000020000080
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000016 R14: 00007f4c29189000 R15: 00000000200000c0

Showing all locks held in the system:
4 locks held by kworker/u4:2/37:
#0: 00000000a6e3784e ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 00000000e0eb0f2f (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 000000004fabc36d (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521
#3: 0000000052e12988 (rtnl_mutex){+.+.}, at: cangw_pernet_exit+0xe/0x20 net/can/gw.c:1032
1 lock held by khungtaskd/1570:
#0: 00000000da7a351b (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
3 locks held by kworker/0:2/3394:
#0: 0000000012173a4b ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 0000000074064fb2 ((linkwatch_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 0000000052e12988 (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236
2 locks held by systemd-udevd/4696:
#0: 0000000055458930 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478
#1: 00000000c0c2513b (loop_ctl_mutex){+.+.}, at: lo_open+0x19/0xd0 drivers/block/loop.c:1771
1 lock held by in:imklog/7771:
#0: 0000000081d7ccb8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
2 locks held by syz-executor.1/8137:
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: tun_detach drivers/net/tun.c:759 [inline]
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3323
#1: 00000000e3c26dcd (cpu_hotplug_lock.rw_sem){++++}, at: get_online_cpus include/linux/cpu.h:137 [inline]
#1: 00000000e3c26dcd (cpu_hotplug_lock.rw_sem){++++}, at: flush_all_backlogs net/core/dev.c:5276 [inline]
#1: 00000000e3c26dcd (cpu_hotplug_lock.rw_sem){++++}, at: rollback_registered_many+0x3a8/0xe70 net/core/dev.c:8181
1 lock held by syz-executor.2/8139:
#0: 0000000055458930 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478
2 locks held by syz-executor.5/8145:
#0: 00000000d67a2cc7 (&type->s_umount_key#37){++++}, at: deactivate_super+0x16c/0x1a0 fs/super.c:359
#1: 00000000abb53be2 (lock#6){+.+.}, at: lru_add_drain_all+0x5a/0x4d0 mm/swap.c:681
3 locks held by kworker/0:3/9213:
#0: 00000000ab25c230 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 0000000045af3da3 ((addr_chk_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 0000000052e12988 (rtnl_mutex){+.+.}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4476
1 lock held by syz-executor.0/9525:
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: tun_detach drivers/net/tun.c:759 [inline]
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3323
1 lock held by syz-executor.4/10287:
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: tun_detach drivers/net/tun.c:759 [inline]
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3323
2 locks held by syz-executor.3/11394:
#0: 00000000c0c2513b (loop_ctl_mutex){+.+.}, at: __loop_clr_fd+0x88/0xe50 drivers/block/loop.c:1080
#1: 00000000abb53be2 (lock#6){+.+.}, at: lru_add_drain_all+0x5a/0x4d0 mm/swap.c:681
1 lock held by syz-executor.1/11425:
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
#0: 0000000052e12988 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779

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

NMI backtrace for cpu 0
CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
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+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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 11300 Comm: syz-executor.5 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mark_lock+0x1c/0x1160 kernel/locking/lockdep.c:3099
Code: 00 eb 87 4c 89 ff e8 43 7c 4d 00 eb c7 90 48 b8 00 00 00 00 00 fc ff df 41 57 89 d1 41 89 d7 41 56 4c 8d 76 20 4c 89 f2 41 55 <49> 89 fd 41 54 48 c1 ea 03 41 bc 01 00 00 00 55 41 d3 e4 48 89 f5
RSP: 0000:ffff8880aaeff930 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000008
RDX: ffff88804b98ea90 RSI: ffff88804b98ea70 RDI: ffff88804b98e1c0
RBP: ffff88804b98ea92 R08: 0000000000000001 R09: 0000000000000001
R10: ffff88804b98ea70 R11: 0000000000000000 R12: 00000000000c0001
R13: ffff88804b98e1c0 R14: ffff88804b98ea90 R15: 0000000000000008
FS: 00007f2638856700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f263b287b11 CR3: 000000009aeae000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__lock_acquire+0x6de/0x3ff0 kernel/locking/lockdep.c:3377
lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:152
__debug_check_no_obj_freed lib/debugobjects.c:776 [inline]
debug_check_no_obj_freed+0xb5/0x490 lib/debugobjects.c:817
kmem_cache_free+0xff/0x260 mm/slab.c:3764
__sigqueue_free kernel/signal.c:448 [inline]
dequeue_synchronous_signal kernel/signal.c:737 [inline]
get_signal+0xd6b/0x1f70 kernel/signal.c:2479
do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode+0x277/0x2d0 arch/x86/entry/common.c:198
retint_user+0x8/0x18
RIP: 0033:0x7f263b287452
Code: ff e8 62 33 01 00 85 c0 0f 84 ba 01 00 00 64 f0 83 2c 25 b8 ff ff ff 01 e8 6b d1 00 00 48 8b 0c 24 8b 00 48 8b 99 80 00 00 00 <89> 81 88 00 00 00 85 c0 75 06 48 83 fb ff 74 18 48 63 44 24 14 48
RSP: 002b:00007f26388561a0 EFLAGS: 00010203
RAX: 0000000000000013 RBX: 00000002be5741c3 RCX: 00007f263b287a89
RDX: 00007f263b28742e RSI: 0000000000000001 RDI: 00007f26388565f0
RBP: 00007f263b33af6d R08: 00007f26388561a0 R09: 00007f263b33af6d
R10: 00007f263b33a78f R11: 0000000000000000 R12: 0000000000000000
R13: 00007ffe18ca794f R14: 00007f2638856300 R15: 0000000000022000
----------------
Code disassembly (best guess):
0: 00 eb add %ch,%bl
2: 87 4c 89 ff xchg %ecx,-0x1(%rcx,%rcx,4)
6: e8 43 7c 4d 00 callq 0x4d7c4e
b: eb c7 jmp 0xffffffd4
d: 90 nop
e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
15: fc ff df
18: 41 57 push %r15
1a: 89 d1 mov %edx,%ecx
1c: 41 89 d7 mov %edx,%r15d
1f: 41 56 push %r14
21: 4c 8d 76 20 lea 0x20(%rsi),%r14
25: 4c 89 f2 mov %r14,%rdx
28: 41 55 push %r13
* 2a: 49 89 fd mov %rdi,%r13 <-- trapping instruction
2d: 41 54 push %r12
2f: 48 c1 ea 03 shr $0x3,%rdx
33: 41 bc 01 00 00 00 mov $0x1,%r12d
39: 55 push %rbp
3a: 41 d3 e4 shl %cl,%r12d
3d: 48 89 f5 mov %rsi,%rbp


---
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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.