general protection fault in batadv_iv_ogm_queue_add

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 3880be62 Add linux-next specific files for 20190807
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15694c1c600000
kernel config: https://syzkaller.appspot.com/x/.config?x=6005b7ece314b33e
dashboard link: https://syzkaller.appspot.com/bug?extid=7a41b091af30baac994d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [a...@unstable.cc b.a.t...@lists.open-mesh.org
da...@davemloft.net linux-...@vger.kernel.org marekl...@neomailbox.ch
net...@vger.kernel.org s...@simonwunderlich.de]

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+7a41b0...@syzkaller.appspotmail.com

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
CPU: 0 PID: 19012 Comm: kworker/u4:8 Not tainted 5.3.0-rc3-next-20190807 #61
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:batadv_iv_ogm_queue_add+0x49/0x1120
net/batman-adv/bat_iv_ogm.c:599
Code: 48 89 75 b8 48 89 4d c0 4c 89 45 b0 44 89 4d d0 e8 9c 8a 52 fa 48 8d
7b 03 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48
89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 18 0d 00 00
RSP: 0018:ffff888064c9fb78 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88808fae6d00
RDX: 0000000000000000 RSI: ffffffff871f8214 RDI: 0000000000000003
RBP: ffff888064c9fc10 R08: ffff88808fae6d00 R09: 0000000000000001
R10: ffffed10110cad1f R11: ffff8880886568ff R12: ffff8880886568fc
R13: 000000010000cef0 R14: ffff88808fae6d00 R15: 000000010000cf56
FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001c58000 CR3: 000000009a94c000 CR4: 00000000001426f0
Call Trace:
batadv_iv_ogm_schedule+0x783/0xe50 net/batman-adv/bat_iv_ogm.c:791
batadv_iv_send_outstanding_bat_ogm_packet+0x5ba/0x760
net/batman-adv/bat_iv_ogm.c:1669
process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
worker_thread+0x98/0xe40 kernel/workqueue.c:2415
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 23ab42c1282b7591 ]---
RIP: 0010:batadv_iv_ogm_queue_add+0x49/0x1120
net/batman-adv/bat_iv_ogm.c:599
Code: 48 89 75 b8 48 89 4d c0 4c 89 45 b0 44 89 4d d0 e8 9c 8a 52 fa 48 8d
7b 03 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48
89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 18 0d 00 00
RSP: 0018:ffff888064c9fb78 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88808fae6d00
RDX: 0000000000000000 RSI: ffffffff871f8214 RDI: 0000000000000003
RBP: ffff888064c9fc10 R08: ffff88808fae6d00 R09: 0000000000000001
R10: ffffed10110cad1f R11: ffff8880886568ff R12: ffff8880886568fc
R13: 000000010000cef0 R14: ffff88808fae6d00 R15: 000000010000cf56
FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001c58000 CR3: 000000009a94c000 CR4: 00000000001426f0


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[Dmitry Vyukov]

#syz upstream

> --
> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-upstream-m...@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/0000000000006b30ed058f93342b%40google.com.