WARNING in batadv_mcast_mla_update

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 58b454eb Linux 4.14.112
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12555ca0a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=8b0e7ab7678533ab
dashboard link: https://syzkaller.appspot.com/bug?extid=7d3e799c87a3e3d781ba
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+7d3e79...@syzkaller.appspotmail.com

team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
------------[ cut here ]------------
WARNING: CPU: 1 PID: 2283 at net/batman-adv/multicast.c:315
batadv_mcast_mla_tt_add net/batman-adv/multicast.c:315 [inline]
WARNING: CPU: 1 PID: 2283 at net/batman-adv/multicast.c:315
__batadv_mcast_mla_update net/batman-adv/multicast.c:578 [inline]
WARNING: CPU: 1 PID: 2283 at net/batman-adv/multicast.c:315
batadv_mcast_mla_update+0x1599/0x1b00 net/batman-adv/multicast.c:603
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 2283 Comm: kworker/u4:5 Not tainted 4.14.112 #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: bat_events batadv_mcast_mla_update
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x19c lib/dump_stack.c:53
panic+0x1f2/0x438 kernel/panic.c:182
__warn.cold+0x2f/0x34 kernel/panic.c:546
report_bug+0x216/0x254 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:944
RIP: 0010:batadv_mcast_mla_tt_add net/batman-adv/multicast.c:315 [inline]
RIP: 0010:__batadv_mcast_mla_update net/batman-adv/multicast.c:578 [inline]
RIP: 0010:batadv_mcast_mla_update+0x1599/0x1b00
net/batman-adv/multicast.c:603
RSP: 0018:ffff8880a1a37bf8 EFLAGS: 00010297
RAX: ffff8880a1a1c100 RBX: ffff8880a1a37cf0 RCX: 1ffff11014343939
RDX: 0000000000000000 RSI: ffff8880a1a1c9a8 RDI: 0000000000000286
RBP: ffff8880a1a37d38 R08: 000000003a308b90 R09: ffff8880a1a1c9c8
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a1a37cf0
R13: ffff888065e3c300 R14: ffff888065e3d384 R15: ffff8880a1a37d10
process_one_work+0x868/0x1610 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x31c/0x430 kernel/kthread.c:232
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

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