skbuff: skb_over_panic: text:00000000f4e4ca50 len:56 put:8 head:00000000965be747 data:000000008d3601cd 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: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.14.156-syzkaller #0 Workqueue: ipv6_addrconf addrconf_dad_work task: 000000004044d17b task.stack: 00000000c867dfb9 RIP: 0010:skb_panic+0x16c/0x16e net/core/skbuff.c:104 RSP: 0018:ffff8881daa2f868 EFLAGS: 00010286 RAX: 0000000000000085 RBX: ffff8881c7a86dc0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b46a420 RDI: ffffed103b545eff RBP: ffffffff8b68a0a0 R08: 0000000000000085 R09: ffffed103b744ce9 R10: ffffed103b744ce8 R11: ffff8881dba26747 R12: ffffffff8ad8600e R13: 0000000000000008 R14: ffff88819ea0a200 R15: 00000000000000c0 FS: 0000000000000000(0000) GS:ffff8881dba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f941d3c2270 CR3: 0000000095c26006 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 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 c0 9a 68 8b ff 74 24 10 ff 74 24 20 e8 49 a3 ee fe <0f> 0b e8 e7 7d fd fe 4c 8b 64 24 18 e8 bd 43 20 ff 48 c7 c1 60 RIP: skb_panic+0x16c/0x16e net/core/skbuff.c:104 RSP: ffff8881daa2f868 ---[ end trace 9c8782614a8307ed ]---