panic: text:ADDR len:LINE put:LINE head:ADDR data:ADDR tail:LINExc8 end:LINExc0 dev:ip6tnl0

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f7fedd5c ANDROID: overlayfs: add __get xattr method
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=14f7923ae00000
kernel config: https://syzkaller.appspot.com/x/.config?x=844cb28a0c5c98da
dashboard link: https://syzkaller.appspot.com/bug?extid=71faf076c8ded2b8234d
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+71faf0...@syzkaller.appspotmail.com

skbuff: skb_over_panic: text:00000000f7fc6b47 len:56 put:8
head:000000009d251125 data:00000000b11dc5dc tail:0xc8 end:0xc0 dev:ip6tnl0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:104!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
Modules linked in:
CPU: 1 PID: 68 Comm: kworker/1:1 Not tainted 4.14.152+ #0
Workqueue: ipv6_addrconf addrconf_dad_work
task: 000000009476b587 task.stack: 00000000a9b86940
RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:104
RSP: 0018:ffff8881d2cef868 EFLAGS: 00010286
RAX: 0000000000000085 RBX: ffff88819f3b93c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffffb246a080 RDI: ffffed103a59deff
RBP: ffffffffb2689c20 R08: 0000000000000085 R09: ffffed103aee4ce9
R10: ffffed103aee4ce8 R11: ffff8881d7726747 R12: ffffffffb1d8480e
R13: 0000000000000008 R14: ffff88819e1b6600 R15: 00000000000000c0
FS: 0000000000000000(0000) GS:ffff8881d7700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe5cb93d9c CR3: 00000001f4226004 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
skb_over_panic net/core/skbuff.c:109 [inline]
skb_put.cold+0x24/0x24 net/core/skbuff.c:1699
mld_newpack+0x4ce/0x7a0 net/ipv6/mcast.c:1608
add_grhead.isra.0+0x29c/0x370 net/ipv6/mcast.c:1691
add_grec+0x6a3/0xf10 net/ipv6/mcast.c:1822
mld_send_initial_cr.part.0+0xb1/0x140 net/ipv6/mcast.c:2072
mld_send_initial_cr net/ipv6/mcast.c:2090 [inline]
ipv6_mc_dad_complete+0x163/0x1b0 net/ipv6/mcast.c:2084
addrconf_dad_completed+0x7eb/0xad0 net/ipv6/addrconf.c:4079
addrconf_dad_begin net/ipv6/addrconf.c:3867 [inline]
addrconf_dad_work+0x99e/0x1170 net/ipv6/addrconf.c:3969
process_one_work+0x7f1/0x1580 kernel/workqueue.c:2134
worker_thread+0xdd/0xdf0 kernel/workqueue.c:2271
kthread+0x31f/0x430 kernel/kthread.c:232
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404
Code: 20 ff 4c 8b 4c 24 10 8b 4b 78 41 56 45 89 e8 4c 89 e2 41 57 48 89 ee
48 c7 c7 40 96 68 b2 ff 74 24 10 ff 74 24 20 e8 39 b7 ee fe <0f> 0b e8 d7
91 fd fe 4c 8b 64 24 18 e8 fd 54 20 ff 48 c7 c1 e0
RIP: skb_panic+0x16c/0x16e net/core/skbuff.c:104 RSP: ffff8881d2cef868
---[ end trace 45d9a659e73a6ea5 ]---


---
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[syzbot]

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