KASAN: user-memory-access Write in batadv_purge_orig_ref

[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=173bfd1d700000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=32c6441490cb0a9d5ed1
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+32c644...@syzkaller.appspotmail.com

netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'.
device bond3 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): bond3: link is not ready
==================================================================
BUG: KASAN: user-memory-access in atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
BUG: KASAN: user-memory-access in __lock_acquire+0x251/0x3ff0 kernel/locking/lockdep.c:3308
8021q: adding VLAN 0 to HW filter on device bond3
Write of size 4 at addr 0000770007700138 by task kworker/u4:3/28203

CPU: 1 PID: 28203 Comm: kworker/u4:3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_purge_orig
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
kasan_report_error.cold+0x15b/0x1b9 mm/kasan/report.c:352
netlink: 88 bytes leftover after parsing attributes in process `syz-executor.0'.
kasan_report+0x8f/0xa0 mm/kasan/report.c:412
atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
__lock_acquire+0x251/0x3ff0 kernel/locking/lockdep.c:3308
lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:334 [inline]
batadv_purge_orig_ref+0x16d/0x1110 net/batman-adv/originator.c:1363
batadv_purge_orig+0x17/0x60 net/batman-adv/originator.c:1392
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
==================================================================


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[syzbot]

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