skbuff: skb_over_panic: text:ffffffff863aff4f len:40 put:40 head:ffff8880afee00c0 data:ffff8880afee1ee0 tail:0x1e48 end:0xec0 dev:ip6gretap0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:104! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.14.227-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work task: ffff8880b5fdc0c0 task.stack: ffff8880b5fe0000 RIP: 0010:skb_panic+0x172/0x174 net/core/skbuff.c:104 RSP: 0018:ffff8880b5fe78d0 EFLAGS: 00010282 RAX: 000000000000008c RBX: ffff8880a9ffb400 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff878bbbc0 RDI: ffffed1016bfcf10 RBP: ffffffff88555de0 R08: 000000000000008c R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff863aff4f R13: 0000000000000028 R14: ffff8880b3b444c0 R15: 0000000000000ec0 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004bd370 CR3: 0000000008e6a000 CR4: 00000000001406f0 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:1708 ip6_mc_hdr.constprop.0+0x11f/0x580 net/ipv6/mcast.c:1552 mld_newpack+0x3aa/0x720 net/ipv6/mcast.c:1603 add_grhead+0x265/0x330 net/ipv6/mcast.c:1691 add_grec+0xc40/0xed0 net/ipv6/mcast.c:1822 mld_send_initial_cr.part.0+0xb0/0x140 net/ipv6/mcast.c:2072 mld_send_initial_cr net/ipv6/mcast.c:1170 [inline] ipv6_mc_dad_complete+0x183/0x5a0 net/ipv6/mcast.c:2084 addrconf_dad_completed+0x80f/0xa40 net/ipv6/addrconf.c:4061 addrconf_dad_work+0x5f2/0xef0 net/ipv6/addrconf.c:3992 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 8b 4c 24 10 8b 8b 80 00 00 00 41 56 45 89 e8 4c 89 e2 41 57 48 89 ee 48 c7 c7 80 56 55 88 ff 74 24 10 ff 74 24 20 e8 d9 71 e4 ff <0f> 0b e8 0e d4 39 fa 4c 8b 64 24 18 e8 64 46 63 fa 48 c7 c1 a0 RIP: skb_panic+0x172/0x174 net/core/skbuff.c:104 RSP: ffff8880b5fe78d0 ---[ end trace d3c7159bbde51a54 ]---