kernel BUG in validate_xmit_skb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2c8a3fce Linux 4.14.218
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15d35088d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=80e596b8b0902d96
dashboard link: https://syzkaller.appspot.com/bug?extid=df827b4838ef76799a16

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+df827b...@syzkaller.appspotmail.com

audit: type=1804 audit(1612929773.452:35): pid=11194 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir014007831/syzkaller.qcG2yG/33/file0/bus" dev="ramfs" ino=32835 res=1
team0: Cannot enslave team device to itself
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'.
------------[ cut here ]------------
kernel BUG at net/core/dev.c:2648!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 11202 Comm: syz-executor.5 Not tainted 4.14.218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a42e6180 task.stack: ffff88805da00000
RIP: 0010:skb_checksum_help+0x638/0x7d0 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:2648
RSP: 0018:ffff88805da07088 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 00000000000003d2 RCX: ffffc900133e6000
RDX: 000000000000a18a RSI: ffffffff85c08e78 RDI: ffff8880a1b9e45a
RBP: ffff8880a1b9e3c0 R08: ffff8880a1b9e440 R09: 00000000000202b4
R10: ffff8880a42e6aa8 R11: ffff8880a42e6180 R12: ffff8880a1b9e444
R13: ffff8880a1b9e48c R14: ffff8880a1b9e450 R15: 000000000000534c
FS: 00007f1bbefa3700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f522000 CR3: 0000000094425000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
skb_csum_hwoffload_help+0x6d/0xf0 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:3055
validate_xmit_skb+0x77a/0x9f0 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:3097
__dev_queue_xmit+0x816/0x2480 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:3513
neigh_hh_output syzkaller/managers/linux-4-14/kernel/./include/net/neighbour.h:490 [inline]
neigh_output syzkaller/managers/linux-4-14/kernel/./include/net/neighbour.h:498 [inline]
ip_finish_output2+0x9db/0x1340 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_output.c:230
ip_finish_output+0x37c/0xc50 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_output.c:318
NF_HOOK_COND syzkaller/managers/linux-4-14/kernel/./include/linux/netfilter.h:239 [inline]
ip_output+0x1cd/0x510 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_output.c:406
dst_output syzkaller/managers/linux-4-14/kernel/./include/net/dst.h:470 [inline]
ip_local_out+0x93/0x170 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_output.c:125
iptunnel_xmit+0x5cc/0x950 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_tunnel_core.c:91
geneve_xmit_skb syzkaller/managers/linux-4-14/kernel/drivers/net/geneve.c:864 [inline]
geneve_xmit+0xc94/0x2880 syzkaller/managers/linux-4-14/kernel/drivers/net/geneve.c:942
__netdev_start_xmit syzkaller/managers/linux-4-14/kernel/./include/linux/netdevice.h:4039 [inline]
netdev_start_xmit syzkaller/managers/linux-4-14/kernel/./include/linux/netdevice.h:4048 [inline]
xmit_one syzkaller/managers/linux-4-14/kernel/net/core/dev.c:3005 [inline]
dev_hard_start_xmit+0x188/0x890 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:3021
sch_direct_xmit+0x251/0x500 syzkaller/managers/linux-4-14/kernel/net/sched/sch_generic.c:186
qdisc_restart syzkaller/managers/linux-4-14/kernel/net/sched/sch_generic.c:249 [inline]
__qdisc_run+0x25d/0xe00 syzkaller/managers/linux-4-14/kernel/net/sched/sch_generic.c:257
__dev_xmit_skb syzkaller/managers/linux-4-14/kernel/net/core/dev.c:3231 [inline]
__dev_queue_xmit+0x13ac/0x2480 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:3489
packet_snd+0x1393/0x21e0 syzkaller/managers/linux-4-14/kernel/net/packet/af_packet.c:3024
packet_sendmsg+0x1139/0x2ad0 syzkaller/managers/linux-4-14/kernel/net/packet/af_packet.c:3049
sock_sendmsg_nosec syzkaller/managers/linux-4-14/kernel/net/socket.c:646 [inline]
sock_sendmsg+0xb5/0x100 syzkaller/managers/linux-4-14/kernel/net/socket.c:656
SYSC_sendto syzkaller/managers/linux-4-14/kernel/net/socket.c:1763 [inline]
SyS_sendto+0x1c7/0x2c0 syzkaller/managers/linux-4-14/kernel/net/socket.c:1731
do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x465b09
RSP: 002b:00007f1bbefa3188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09
RDX: 0000000000003287 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000004b069f R08: 0000000000000000 R09: 00000000000002ff
R10: 0000000004000002 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffe159e698f R14: 00007f1bbefa3300 R15: 0000000000022000
Code: be fb e9 c5 fd ff ff e8 47 90 94 fb 48 89 ef 41 bc ea ff ff ff e8 f9 f8 ff ff e9 4c fe ff ff e8 2f 90 94 fb 0f 0b e8 28 90 94 fb <0f> 0b 4c 89 f7 e8 6e 09 be fb e9 f5 f9 ff ff 4c 89 f7 e8 f1 0c
RIP: skb_checksum_help+0x638/0x7d0 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:2648 RSP: ffff88805da07088
---[ end trace 4562b2118eb7ac5b ]---


---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

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