general protection fault in batadv_iv_ogm_queue_add

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: ddef1e8e Linux 4.14.151
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12c2ea8ae00000
kernel config: https://syzkaller.appspot.com/x/.config?x=a2b317f0c5f02ed3
dashboard link: https://syzkaller.appspot.com/bug?extid=14f7416a2ac72145e08f
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+14f741...@syzkaller.appspotmail.com

batman_adv: batadv0: Removing interface: veth521
batman_adv: batadv0: Interface deactivated: veth539
batman_adv: batadv0: Removing interface: veth539
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: 0 PID: 544 Comm: kworker/u4:5 Not tainted 4.14.151 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
task: ffff8880a8e1a1c0 task.stack: ffff8880a8e28000
RIP: 0010:batadv_iv_ogm_queue_add+0x40/0xf80 net/batman-adv/bat_iv_ogm.c:778
RSP: 0018:ffff8880a8e2fb68 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88808c569000 RCX: ffff8880964f0cc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: ffff8880a8e2fc00 R08: ffff88808c569000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880964f0cc0 R14: ffff88806a222680 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c436cbd000 CR3: 000000009e803000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
batadv_iv_ogm_schedule+0x9c5/0xd20 net/batman-adv/bat_iv_ogm.c:982
batadv_iv_send_outstanding_bat_ogm_packet+0x4a1/0x680
net/batman-adv/bat_iv_ogm.c:1809
process_one_work+0x863/0x1600 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: ec 70 89 55 d0 48 89 4d c8 4c 89 45 b8 44 89 4d c4 e8 05 b7 5b fb 49
8d 7f 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 83 0a 00
RIP: batadv_iv_ogm_queue_add+0x40/0xf80 net/batman-adv/bat_iv_ogm.c:778
RSP: ffff8880a8e2fb68
---[ end trace 01c9bb314d642548 ]---


---
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: c1141b3a Linux 4.14.166
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17305601e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=a99b4b74c4c01851

dashboard link: https://syzkaller.appspot.com/bug?extid=14f7416a2ac72145e08f
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15711a95e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+14f741...@syzkaller.appspotmail.com

batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1

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: 0 PID: 7602 Comm: kworker/u4:6 Not tainted 4.14.166-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet

task: ffff8880a7f40440 task.stack: ffff88808fcc8000
RIP: 0010:batadv_iv_ogm_queue_add+0x40/0xe30 net/batman-adv/bat_iv_ogm.c:778
RSP: 0018:ffff88808fccfb58 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88808ba9dac0 RCX: ffff88808ba9dac0

RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003

RBP: ffff88808fccfc00 R08: ffff88808ba9dac0 R09: 0000000000000001
R10: ffff8880a7f40d10 R11: ffff8880a7f40440 R12: 0000000000000006
R13: ffff888090951440 R14: ffff88808ba9dae8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007fff40a5deec CR3: 0000000093b6f000 CR4: 00000000001406f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

batadv_iv_ogm_schedule+0xa61/0xe20 net/batman-adv/bat_iv_ogm.c:982

batadv_iv_send_outstanding_bat_ogm_packet+0x4a1/0x680 net/batman-adv/bat_iv_ogm.c:1809
process_one_work+0x863/0x1600 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Code: c4 80 89 55 d0 48 89 4d c8 4c 89 45 b8 44 89 4d c4 e8 35 38 0f fb 49 8d 7f 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 ee 0b 00
RIP: batadv_iv_ogm_queue_add+0x40/0xe30 net/batman-adv/bat_iv_ogm.c:778 RSP: ffff88808fccfb58
---[ end trace ac0a68c49ffb76e1 ]---