INFO: task hung in netdev_run_todo

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 555161ee Linux 4.19.76
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17a52635600000
kernel config: https://syzkaller.appspot.com/x/.config?x=2520883f3190ad39
dashboard link: https://syzkaller.appspot.com/bug?extid=829decb0d730f5f2ddd1
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+829dec...@syzkaller.appspotmail.com

bridge0: port 2(bridge_slave_1) entered disabled state
bridge0: port 1(bridge_slave_0) entered disabled state
bridge0: port 2(bridge_slave_1) entered disabled state
bridge0: port 1(bridge_slave_0) entered disabled state
INFO: task kworker/u4:6:9484 blocked for more than 140 seconds.
Not tainted 4.19.76 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:6 D26896 9484 2 0x80000000
Workqueue: netns cleanup_net
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_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
netdev_run_todo+0x4d4/0x7a0 net/core/dev.c:8798
rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:117
ip_tunnel_delete_nets+0x423/0x5f0 net/ipv4/ip_tunnel.c:1074
ipgre_exit_batch_net+0x23/0x30 net/ipv4/ip_gre.c:1073
ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:156
cleanup_net+0x3fb/0x960 net/core/net_namespace.c:552
process_one_work+0x989/0x1750 kernel/workqueue.c:2153
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
INFO: task syz-executor.3:31902 blocked for more than 140 seconds.
Not tainted 4.19.76 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D27440 31902 9545 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_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock net/core/rtnetlink.c:77 [inline]
rtnetlink_rcv_msg+0x40a/0xb00 net/core/rtnetlink.c:4744
netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a29
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f97fdfacc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a29
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f97fdfad6d4
R13: 00000000004c7968 R14: 00000000004dd3c0 R15: 00000000ffffffff
INFO: task syz-executor.3:31905 blocked for more than 140 seconds.
Not tainted 4.19.76 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D29464 31905 9545 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_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
do_ip_setsockopt.isra.0+0x130/0x3dd0 net/ipv4/ip_sockglue.c:642
ip_setsockopt+0x49/0x100 net/ipv4/ip_sockglue.c:1246
raw_setsockopt+0xe0/0x100 net/ipv4/raw.c:861
sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3041
__sys_setsockopt+0x17a/0x280 net/socket.c:1901
__do_sys_setsockopt net/socket.c:1912 [inline]
__se_sys_setsockopt net/socket.c:1909 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1909
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a29
Code: Bad RIP value.
RSP: 002b:00007f97fdf8bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459a29
RDX: 0000000000000026 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 000000000075bfc8 R08: 000000000000000c R09: 0000000000000000
R10: 00000000200001c0 R11: 0000000000000246 R12: 00007f97fdf8c6d4
R13: 00000000004c81d4 R14: 00000000004de338 R15: 00000000ffffffff
INFO: task syz-executor.5:31904 blocked for more than 140 seconds.
Not tainted 4.19.76 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D28624 31904 9581 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_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
sock_do_ioctl+0x24e/0x2f0 net/socket.c:963
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a29
Code: Bad RIP value.
RSP: 002b:00007f8c310dfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a29
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000006
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8c310e06d4
R13: 00000000004c33e9 R14: 00000000004d6d60 R15: 00000000ffffffff

Showing all locks held in the system:
3 locks held by kworker/0:1/14:
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at: atomic64_set
include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at: atomic_long_set
include/asm-generic/atomic-long.h:59 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at: set_work_data
kernel/workqueue.c:617 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 00000000d5963210 (deferred_process_work){+.+.}, at:
process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
#2: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by khungtaskd/1038:
#0: 00000000399b1ac8 (rcu_read_lock){....}, at:
debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
3 locks held by kworker/0:2/3225:
#0: 000000007f50d791 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 000000007f50d791 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 000000007f50d791 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 000000007f50d791 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 000000007f50d791 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_data kernel/workqueue.c:617 [inline]
#0: 000000007f50d791 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 000000007f50d791 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 00000000c1e31ec1 ((addr_chk_work).work){+.+.}, at:
process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
#2: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by rsyslogd/7417:
#0: 0000000042b066d8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
fs/file.c:767
2 locks held by getty/7539:
#0: 000000000ff6e262 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000639ecc52 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7540:
#0: 000000004e24acde (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000d1bf69c9 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7541:
#0: 000000003bfea20c (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000ac8bfb52 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7542:
#0: 000000004e9041d4 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000008bb887d2 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7543:
#0: 0000000061f578d1 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000589cd482 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7544:
#0: 000000006537baa7 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000c69f503b (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7545:
#0: 00000000de03d02b (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000002b7c3c27 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
3 locks held by kworker/0:3/7587:
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at: atomic64_set
include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at: atomic_long_set
include/asm-generic/atomic-long.h:59 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at: set_work_data
kernel/workqueue.c:617 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 0000000037bd4036 ((wq_completion)"events"){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 0000000042e034cf ((linkwatch_work).work){+.+.}, at:
process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
#2: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
2 locks held by kworker/0:4/7592:
#0: 000000006923833c ((wq_completion)"rcu_gp"){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 000000006923833c ((wq_completion)"rcu_gp"){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 000000006923833c ((wq_completion)"rcu_gp"){+.+.}, at: atomic64_set
include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 000000006923833c ((wq_completion)"rcu_gp"){+.+.}, at: atomic_long_set
include/asm-generic/atomic-long.h:59 [inline]
#0: 000000006923833c ((wq_completion)"rcu_gp"){+.+.}, at: set_work_data
kernel/workqueue.c:617 [inline]
#0: 000000006923833c ((wq_completion)"rcu_gp"){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 000000006923833c ((wq_completion)"rcu_gp"){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 00000000e2a33a6b ((work_completion)(&rew.rew_work)){+.+.}, at:
process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
4 locks held by kworker/u4:6/9484:
#0: 00000000ac0d51c1 ((wq_completion)"%s""netns"){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 00000000ac0d51c1 ((wq_completion)"%s""netns"){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 00000000ac0d51c1 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set
include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 00000000ac0d51c1 ((wq_completion)"%s""netns"){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 00000000ac0d51c1 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data
kernel/workqueue.c:617 [inline]
#0: 00000000ac0d51c1 ((wq_completion)"%s""netns"){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 00000000ac0d51c1 ((wq_completion)"%s""netns"){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 00000000a74765f5 (net_cleanup_work){+.+.}, at:
process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
#2: 0000000049003ae2 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x960
net/core/net_namespace.c:519
#3: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.2/31588:
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.0/31597:
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.1/31539:
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
2 locks held by syz-executor.4/31800:
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock
net/core/rtnetlink.c:77 [inline]
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x40a/0xb00
net/core/rtnetlink.c:4744
#1: 00000000810cacde (rcu_preempt_state.exp_mutex){+.+.}, at:
exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
#1: 00000000810cacde (rcu_preempt_state.exp_mutex){+.+.}, at:
_synchronize_rcu_expedited+0x59e/0x7f0 kernel/rcu/tree_exp.h:667
1 lock held by syz-executor.3/31902:
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock
net/core/rtnetlink.c:77 [inline]
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x40a/0xb00
net/core/rtnetlink.c:4744
1 lock held by syz-executor.3/31905:
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.5/31904:
#0: 0000000002945ddc (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77

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

NMI backtrace for cpu 1
CPU: 1 PID: 1038 Comm: khungtaskd Not tainted 4.19.76 #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+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: 10306 Comm: kworker/u4:8 Not tainted 4.19.76 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:mark_held_locks+0xb1/0x100 kernel/locking/lockdep.c:2805
Code: 03 83 e2 07 42 0f b6 04 38 38 d0 7f 04 84 c0 75 4d 0f b6 46 22 8b 55
d4 a8 03 41 0f 44 d5 a8 04 74 0c 4c 89 f7 e8 df eb ff ff <85> c0 74 11 83
c3 01 41 39 9e 78 08 00 00 7f ae b8 01 00 00 00 48
RSP: 0018:ffff88805aca7b78 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 1ffff1100dd059c9
RDX: 1ffffffff13e1f28 RSI: ffff88806e82ce28 RDI: ffffffff89f0f940
RBP: ffff88805aca7bb0 R08: ffff88806e82c580 R09: ffff88806e82ce48
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88806e82ce00
R13: 0000000000000002 R14: ffff88806e82c580 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c420681000 CR3: 000000008f852000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__trace_hardirqs_on_caller kernel/locking/lockdep.c:2826 [inline]
lockdep_hardirqs_on+0x19b/0x5d0 kernel/locking/lockdep.c:2879
trace_hardirqs_on+0x67/0x220 kernel/trace/trace_preemptirq.c:30
__local_bh_enable_ip+0x15a/0x270 kernel/softirq.c:194
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_bh+0x31/0x40 kernel/locking/spinlock.c:200
spin_unlock_bh include/linux/spinlock.h:374 [inline]
batadv_nc_purge_paths+0x265/0x370 net/batman-adv/network-coding.c:482
batadv_nc_worker+0x29c/0x760 net/batman-adv/network-coding.c:731
process_one_work+0x989/0x1750 kernel/workqueue.c:2153
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


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[syzbot]

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