Hello,

syzbot found the following crash on:

HEAD commit: 998d7551 Merge branch 'akpm' (patches from Andrew) git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1702db87600000 kernel config: https://syzkaller.appspot.com/x/.config?x=e0ac4d9b35046343 dashboard link: https://syzkaller.appspot.com/bug?extid=7dd2da51d8ae6f990403 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+7dd2da51d8ae6f990403@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: 4256 Comm: kworker/u4:0 Not tainted 5.4.0-rc3+ #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 RIP: 0010:batadv_iv_ogm_queue_add+0x49/0x1120 net/batman-adv/bat_iv_ogm.c:605 Code: 48 89 75 b8 48 89 4d c0 4c 89 45 b0 44 89 4d d0 e8 fc 02 46 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:ffff88805d2cfb80 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888092284000 RDX: 0000000000000000 RSI: ffffffff872d1214 RDI: 0000000000000003 RBP: ffff88805d2cfc18 R08: ffff888092284000 R09: 0000000000000001 R10: ffffed100ba59f77 R11: 0000000000000003 R12: dffffc0000000000 R13: ffffed101245080e R14: ffff888092284000 R15: 0000000100051cf6 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200002c0 CR3: 00000000a421b000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: batadv_iv_ogm_schedule+0xb0b/0xe50 net/batman-adv/bat_iv_ogm.c:813 batadv_iv_send_outstanding_bat_ogm_packet+0x580/0x760 net/batman-adv/bat_iv_ogm.c:1675 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 04d065842187c2b8 ]--- RIP: 0010:batadv_iv_ogm_queue_add+0x49/0x1120 net/batman-adv/bat_iv_ogm.c:605 Code: 48 89 75 b8 48 89 4d c0 4c 89 45 b0 44 89 4d d0 e8 fc 02 46 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:ffff88805d2cfb80 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888092284000 RDX: 0000000000000000 RSI: ffffffff872d1214 RDI: 0000000000000003 RBP: ffff88805d2cfc18 R08: ffff888092284000 R09: 0000000000000001 R10: ffffed100ba59f77 R11: 0000000000000003 R12: dffffc0000000000 R13: ffffed101245080e R14: ffff888092284000 R15: 0000000100051cf6 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200002c0 CR3: 00000000a421b000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

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