net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 executing program syzkaller login: [ 18.259519] syz0: caps=(0x00000400000058c1, 0x0000000000000000) len=159 data_len=0 gso_size=1792 gso_type=3 ip_summed=0 [ 18.260645] ------------[ cut here ]------------ [ 18.261239] WARNING: CPU: 2 PID: 2975 at net/core/dev.c:2585 skb_warn_bad_offload+0x2a9/0x380 [ 18.262055] Kernel panic - not syncing: panic_on_warn set ... [ 18.262055] [ 18.262706] CPU: 2 PID: 2975 Comm: syzkaller315399 Not tainted 4.13.0-next-20170912+ #2 [ 18.263442] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 18.264173] Call Trace: [ 18.264411] dump_stack+0x194/0x257 [ 18.264742] ? arch_local_irq_restore+0x53/0x53 [ 18.265179] panic+0x1e4/0x417 [ 18.265477] ? __warn+0x1d9/0x1d9 [ 18.265794] ? show_regs_print_info+0x65/0x65 [ 18.266223] ? skb_warn_bad_offload+0x2a9/0x380 [ 18.266692] __warn+0x1c4/0x1d9 [ 18.267041] ? skb_warn_bad_offload+0x2a9/0x380 [ 18.267566] report_bug+0x211/0x2d0 [ 18.267946] fixup_bug+0x40/0x90 [ 18.268280] do_trap+0x260/0x390 [ 18.268681] do_error_trap+0x120/0x390 [ 18.269093] ? do_trap+0x390/0x390 [ 18.269457] ? skb_warn_bad_offload+0x2a9/0x380 [ 18.269960] ? vprintk_emit+0x3ea/0x590 [ 18.270373] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 18.270925] do_invalid_op+0x1b/0x20 [ 18.271365] invalid_op+0x18/0x20 [ 18.271711] RIP: 0010:skb_warn_bad_offload+0x2a9/0x380 [ 18.272174] RSP: 0018:ffff88003d9170a0 EFLAGS: 00010282 [ 18.272666] RAX: 000000000000006b RBX: ffff8800694704e0 RCX: 0000000000000000 [ 18.273340] RDX: 000000000000006b RSI: 1ffff10007b22dd4 RDI: ffffed0007b22e08 [ 18.274138] RBP: ffff88003d9170f8 R08: ffff88003d916790 R09: 0000000000000000 [ 18.274808] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880069cb82c0 [ 18.275526] R13: 0000000000000000 R14: ffff880069cb82c0 R15: 0000000000000700 [ 18.276191] __skb_gso_segment+0x607/0x7f0 [ 18.276871] ? skb_mac_gso_segment+0x660/0x660 [ 18.277331] validate_xmit_skb+0x4ba/0xb20 [ 18.277658] ? netif_skb_features+0x8e0/0x8e0 [ 18.277991] validate_xmit_skb_list+0xb7/0x120 [ 18.278383] sch_direct_xmit+0x3b6/0x6d0 [ 18.278803] ? dev_deactivate_queue.constprop.27+0x260/0x260 [ 18.279373] __dev_queue_xmit+0x15fe/0x1e40 [ 18.279832] ? __might_fault+0xe0/0x1d0 [ 18.280200] ? netdev_pick_tx+0x300/0x300 [ 18.280633] ? skb_set_owner_w+0x1ff/0x300 [ 18.280939] ? __might_sleep+0x95/0x190 [ 18.281268] ? kasan_check_write+0x14/0x20 [ 18.281556] ? copyin+0x91/0xb0 [ 18.281824] ? _copy_from_iter+0x367/0xf30 [ 18.282141] ? __check_object_size+0x25d/0x4f0 [ 18.282453] ? check_stack_object+0x140/0x140 [ 18.282791] ? copy_page_to_iter+0xd60/0xd60 [ 18.283154] ? _copy_from_iter_full+0x22b/0xbb0 [ 18.283471] ? __dev_get_by_index+0x1a0/0x1a0 [ 18.283825] ? skb_copy_datagram_from_iter+0x3a5/0x5a0 [ 18.284213] ? iov_iter_advance+0x13f0/0x13f0 [ 18.284517] ? sock_cmsg_send+0x1e1/0x260 [ 18.284850] dev_queue_xmit+0x17/0x20 [ 18.285128] packet_sendmsg+0x3bbf/0x6030 [ 18.285408] ? do_raw_spin_trylock+0x190/0x190 [ 18.285750] ? find_held_lock+0x39/0x1d0 [ 18.286076] ? packet_cached_dev_get+0x2b0/0x2b0 [ 18.286410] ? check_noncircular+0x20/0x20 [ 18.286713] ? lock_release+0xd70/0xd70 [ 18.287020] ? check_same_owner+0x320/0x320 [ 18.287358] ? __check_object_size+0x25d/0x4f0 [ 18.287680] ? __might_sleep+0x95/0x190 [ 18.287963] ? find_held_lock+0x39/0x1d0 [ 18.288256] ? lock_downgrade+0x990/0x990 [ 18.288556] ? sock_has_perm+0x29c/0x400 [ 18.288895] ? selinux_tun_dev_create+0xc0/0xc0 [ 18.289268] ? prandom_u32_state+0x12f/0x180 [ 18.289632] ? lock_release+0xd70/0xd70 [ 18.289919] ? security_socket_sendmsg+0x89/0xb0 [ 18.290286] ? packet_cached_dev_get+0x2b0/0x2b0 [ 18.290662] sock_sendmsg+0xca/0x110 [ 18.290934] ___sys_sendmsg+0x75b/0x8a0 [ 18.291248] ? copy_msghdr_from_user+0x590/0x590 [ 18.291578] ? lock_downgrade+0x990/0x990 [ 18.291904] ? fget_raw+0x20/0x20 [ 18.292188] ? handle_mm_fault+0x410/0x8d0 [ 18.292476] ? __do_page_fault+0x2b8/0xb60 [ 18.292775] ? __fdget+0x18/0x20 [ 18.293025] __sys_sendmsg+0xe5/0x210 [ 18.293300] ? __sys_sendmsg+0xe5/0x210 [ 18.293600] ? SyS_shutdown+0x290/0x290 [ 18.293871] ? __do_page_fault+0xb60/0xb60 [ 18.294193] ? SyS_setsockopt+0x189/0x360 [ 18.294474] ? SyS_setsockopt+0x215/0x360 [ 18.294768] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 18.295142] SyS_sendmsg+0x2d/0x50 [ 18.295387] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 18.295740] RIP: 0033:0x43a699 [ 18.295969] RSP: 002b:00000000007dfe48 EFLAGS: 00000217 ORIG_RAX: 000000000000002e [ 18.296526] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043a699 [ 18.297010] RDX: 0000000020000000 RSI: 0000000020f18000 RDI: 0000000000000004 [ 18.298058] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 18.298559] R10: 0000000000000004 R11: 0000000000000217 R12: 0000000000000000 [ 18.299162] R13: 0000000000402c60 R14: 0000000000402cf0 R15: 0000000000000000 [ 18.299989] Dumping ftrace buffer: [ 18.300338] (ftrace buffer empty) [ 18.300626] Kernel Offset: disabled [ 18.300890] Rebooting in 86400 seconds..