general protection fault in batadv_mcast_mla_update

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d7e78d08 Linux 4.14.195
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16a89b05900000
kernel config: https://syzkaller.appspot.com/x/.config?x=6608b656f49b4e8c
dashboard link: https://syzkaller.appspot.com/bug?extid=f31f483719bc9b557963
compiler: gcc (GCC) 10.1.0-syz 20200507

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+f31f48...@syzkaller.appspotmail.com

netlink: 28 bytes leftover after parsing attributes in process `syz-executor.1'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 2332 Comm: kworker/u4:3 Not tainted 4.14.195-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_mcast_mla_update
task: ffff8880a140c240 task.stack: ffff8880a1418000
RIP: 0010:ether_addr_copy include/linux/etherdevice.h:282 [inline]
RIP: 0010:batadv_mcast_mla_softif_get net/batman-adv/multicast.c:137 [inline]
RIP: 0010:__batadv_mcast_mla_update net/batman-adv/multicast.c:560 [inline]
RIP: 0010:batadv_mcast_mla_update+0xad9/0x1880 net/batman-adv/multicast.c:596
RSP: 0000:ffff8880a141fc20 EFLAGS: 00010202
RAX: ffff8880a140c240 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 00000000ffffffff RDI: 0000000000000010
RBP: dffffc0000000000 R08: ffffffff8951b1d4 R09: ffffffff8951b2d8
R10: 000000000011e05b R11: 0000000000058071 R12: ffff88809f33a1c0
R13: 0000000000000002 R14: ffff8880a996ebc0 R15: ffff8880a141fcf0
FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c023fb7000 CR3: 00000000a87b1000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: ba 18 00 00 00 be 20 00 08 01 e8 a3 26 49 fb 48 85 c0 49 89 c4 0f 84 63 0a 00 00 e8 f2 9e 1f fb 48 8d 7b 10 48 89 fa 48 c1 ea 03 <0f> b6 0c 2a 48 89 fa 83 e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85
RIP: ether_addr_copy include/linux/etherdevice.h:282 [inline] RSP: ffff8880a141fc20
RIP: batadv_mcast_mla_softif_get net/batman-adv/multicast.c:137 [inline] RSP: ffff8880a141fc20
RIP: __batadv_mcast_mla_update net/batman-adv/multicast.c:560 [inline] RSP: ffff8880a141fc20
RIP: batadv_mcast_mla_update+0xad9/0x1880 net/batman-adv/multicast.c:596 RSP: ffff8880a141fc20
---[ end trace 84b42d457019778a ]---


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[syzbot]

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