INFO: task can't die in ip_rt_ioctl

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 49e7e3e9 Add linux-next specific files for 20200929
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1168e46d900000
kernel config: https://syzkaller.appspot.com/x/.config?x=b823d07e241e7aee
dashboard link: https://syzkaller.appspot.com/bug?extid=b2441d2654fdd918e839
compiler: gcc (GCC) 10.1.0-syz 20200507
CC: [da...@davemloft.net ku...@kernel.org kuz...@ms2.inr.ac.ru linux-...@vger.kernel.org net...@vger.kernel.org yosh...@linux-ipv6.org]

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+b2441d...@syzkaller.appspotmail.com

INFO: task syz-executor.0:16010 can't die for more than 143 seconds.
task:syz-executor.0 state:D stack:28504 pid:16010 ppid: 6903 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:3778 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4527
schedule+0xcf/0x270 kernel/sched/core.c:4605
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4664
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
ip_rt_ioctl+0xe6/0x1460 net/ipv4/fib_frontend.c:622
inet_ioctl+0x2d6/0x330 net/ipv4/af_inet.c:937
sock_do_ioctl+0xcb/0x2d0 net/socket.c:1047
sock_ioctl+0x3d5/0x770 net/socket.c:1198
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007fd072e02c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000001ea40 RCX: 000000000045dd99
RDX: 0000000020000080 RSI: 000000000000890b RDI: 0000000000000006
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffc4df415ef R14: 00007fd072e039c0 R15: 000000000118bf2c
INFO: task syz-executor.0:16010 blocked for more than 143 seconds.
Not tainted 5.9.0-rc7-next-20200929-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:28504 pid:16010 ppid: 6903 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:3778 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4527
schedule+0xcf/0x270 kernel/sched/core.c:4605
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4664
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
ip_rt_ioctl+0xe6/0x1460 net/ipv4/fib_frontend.c:622
inet_ioctl+0x2d6/0x330 net/ipv4/af_inet.c:937
sock_do_ioctl+0xcb/0x2d0 net/socket.c:1047
sock_ioctl+0x3d5/0x770 net/socket.c:1198
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007fd072e02c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000001ea40 RCX: 000000000045dd99
RDX: 0000000020000080 RSI: 000000000000890b RDI: 0000000000000006
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffc4df415ef R14: 00007fd072e039c0 R15: 000000000118bf2c
INFO: task syz-executor.5:16040 can't die for more than 144 seconds.
task:syz-executor.5 state:D stack:24224 pid:16040 ppid: 6916 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:3778 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4527
schedule+0xcf/0x270 kernel/sched/core.c:4605
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4664
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5560
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489
netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:671
____sys_sendmsg+0x6e8/0x810 net/socket.c:2362
___sys_sendmsg+0xf3/0x170 net/socket.c:2416
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2449
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007efce637ec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002d3c0 RCX: 000000000045dd99
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffda3363d9f R14: 00007efce637f9c0 R15: 000000000118bf2c
INFO: task syz-executor.5:16040 blocked for more than 144 seconds.
Not tainted 5.9.0-rc7-next-20200929-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5 state:D stack:24224 pid:16040 ppid: 6916 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:3778 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4527
schedule+0xcf/0x270 kernel/sched/core.c:4605
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4664
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5560
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489
netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:671
____sys_sendmsg+0x6e8/0x810 net/socket.c:2362
___sys_sendmsg+0xf3/0x170 net/socket.c:2416
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2449
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007efce637ec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002d3c0 RCX: 000000000045dd99
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffda3363d9f R14: 00007efce637f9c0 R15: 000000000118bf2c
INFO: task syz-executor.5:16042 can't die for more than 145 seconds.
task:syz-executor.5 state:R running task stack:25120 pid:16042 ppid: 6916 flags:0x00004006
Call Trace:
INFO: task syz-executor.5:16067 can't die for more than 145 seconds.
task:syz-executor.5 state:D stack:29608 pid:16067 ppid: 6916 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:3778 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4527
schedule+0xcf/0x270 kernel/sched/core.c:4605
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4664
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1060
sock_ioctl+0x3d5/0x770 net/socket.c:1198
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007efce633cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000013180 RCX: 000000000045dd99
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000007
RBP: 000000000118c0b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118c07c
R13: 00007ffda3363d9f R14: 00007efce633d9c0 R15: 000000000118c07c
INFO: task syz-executor.5:16067 blocked for more than 145 seconds.
Not tainted 5.9.0-rc7-next-20200929-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5 state:D stack:29608 pid:16067 ppid: 6916 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:3778 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4527
schedule+0xcf/0x270 kernel/sched/core.c:4605
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4664
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1060
sock_ioctl+0x3d5/0x770 net/socket.c:1198
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007efce633cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000013180 RCX: 000000000045dd99
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000007
RBP: 000000000118c0b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118c07c
R13: 00007ffda3363d9f R14: 00007efce633d9c0 R15: 000000000118c07c
INFO: task syz-executor.4:16083 blocked for more than 146 seconds.
Not tainted 5.9.0-rc7-next-20200929-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:29608 pid:16083 ppid: 6911 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:3778 [inline]
__schedule+0xec5/0x2200 kernel/sched/core.c:4527
schedule+0xcf/0x270 kernel/sched/core.c:4605
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4664
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1060
sock_ioctl+0x3d5/0x770 net/socket.c:1198
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: Bad RIP value.
RSP: 002b:00007fb2cb092c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000013180 RCX: 000000000045dd99
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000004
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffd8fbebaff R14: 00007fb2cb0939c0 R15: 000000000118bf2c

Showing all locks held in the system:
2 locks held by kworker/u4:0/7:
#0: ffff8880ae5360d8 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1292 [inline]
#0: ffff8880ae5360d8 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x284/0x2200 kernel/sched/core.c:4445
#1: ffff8880ae520ec8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x305/0x440 kernel/sched/psi.c:833
4 locks held by kworker/u4:3/138:
#0: ffff8880a9012138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8880a9012138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff8880a9012138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff8880a9012138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff8880a9012138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff8880a9012138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2240
#1: ffffc90001467da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2244
#2: ffffffff8b6be0b0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:565
#3: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x15/0x160 drivers/net/wireguard/device.c:401
1 lock held by khungtaskd/1157:
#0: ffffffff8a553d00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6221
3 locks held by kworker/0:2/2482:
#0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2240
#1: ffffc900085efda8 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2244
#2: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
1 lock held by in:imklog/6579:
#0: ffff88809e7e6630 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
2 locks held by agetty/6800:
#0: ffff8880991c8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266
#1: ffffc900012102e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a70 drivers/tty/n_tty.c:2156
2 locks held by agetty/6801:
#0: ffff888099d8c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266
#1: ffffc90000f602e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a70 drivers/tty/n_tty.c:2156
3 locks held by kworker/1:4/8212:
#0: ffff888214d25d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888214d25d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
#0: ffff888214d25d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
#0: ffff888214d25d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
#0: ffff888214d25d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
#0: ffff888214d25d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2240
#1: ffffc90015d6fda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2244
#2: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568
1 lock held by syz-executor.0/16010:
#0: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: ip_rt_ioctl+0xe6/0x1460 net/ipv4/fib_frontend.c:622
1 lock held by syz-executor.5/16040:
#0: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5560
1 lock held by syz-executor.5/16042:
1 lock held by syz-executor.5/16067:
#0: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1060
1 lock held by syz-executor.4/16083:
#0: ffffffff8b6cfa88 (rtnl_mutex){+.+.}-{3:3}, at: sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1060

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

NMI backtrace for cpu 0
CPU: 0 PID: 1157 Comm: khungtaskd Not tainted 5.9.0-rc7-next-20200929-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+0x198/0x1fb lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline]
watchdog+0xd89/0xf30 kernel/hung_task.c:339
kthread+0x3af/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.9.0-rc7-next-20200929-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lockdep_softirqs_on+0x177/0x430 kernel/locking/lockdep.c:4189
Code: 02 00 00 41 83 84 24 0c 09 00 00 01 48 b8 00 00 00 00 00 fc ff df 65 4c 8b 24 25 c0 fe 01 00 49 8d bc 24 f0 08 00 00 48 89 fa <48> c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 67 02 00 00 48 8d
RSP: 0018:ffffc90000cdfbe0 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: ffff8880a96441c0 RCX: 0000000000000000
RDX: ffff8880a9644ab0 RSI: 0000000000000000 RDI: ffff8880a9644ab0
RBP: ffffffff87fe5e45 R08: 0000000000000000 R09: ffff88804e7e4fc3
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a96441c0
R13: ffff88804e748c00 R14: dffffc0000000000 R15: ffffffff87fe6080
FS: 0000000000000000(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f76c7059018 CR3: 000000009a77f000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__local_bh_enable_ip+0x165/0x1f0 kernel/softirq.c:183
spin_unlock_bh include/linux/spinlock.h:399 [inline]
batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:470
batadv_nc_worker+0x868/0xe50 net/batman-adv/network-coding.c:721
process_one_work+0x933/0x15a0 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3af/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296


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[syzbot]

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