syzbot

IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
==================================================================
BUG: KMSAN: uninit-value in __ipv6_prefix_equal64_half include/net/ipv6.h:535 [inline]
BUG: KMSAN: uninit-value in ipv6_prefix_equal include/net/ipv6.h:552 [inline]
BUG: KMSAN: uninit-value in check_6rd+0x65c/0x720 net/ipv6/sit.c:771
CPU: 1 PID: 10988 Comm: syz-executor484 Not tainted 4.20.0-rc7+ #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:295
 __ipv6_prefix_equal64_half include/net/ipv6.h:535 [inline]
 ipv6_prefix_equal include/net/ipv6.h:552 [inline]
 check_6rd+0x65c/0x720 net/ipv6/sit.c:771
 try_6rd net/ipv6/sit.c:805 [inline]
 ipip6_tunnel_xmit net/ipv6/sit.c:865 [inline]
 sit_tunnel_xmit+0xb58/0x34d0 net/ipv6/sit.c:1029
 __netdev_start_xmit include/linux/netdevice.h:4356 [inline]
 netdev_start_xmit include/linux/netdevice.h:4365 [inline]
 xmit_one net/core/dev.c:3257 [inline]
 dev_hard_start_xmit+0x607/0xc40 net/core/dev.c:3273
 __dev_queue_xmit+0x2e42/0x3bc0 net/core/dev.c:3843
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3876
 packet_snd net/packet/af_packet.c:2928 [inline]
 packet_sendmsg+0x8306/0x8f30 net/packet/af_packet.c:2953
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xdb9/0x11b0 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441219
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd0f81df68 EFLAGS: 00000286 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000441219
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000006cc018 R08: 0000000000000100 R09: 0000000000000100
R10: 0000000000000100 R11: 0000000000000286 R12: 0000000000402180
R13: 0000000000402210 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:204 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:158
 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2759 [inline]
 __kmalloc_node_track_caller+0xe38/0x1060 mm/slub.c:4383
 __kmalloc_reserve net/core/skbuff.c:137 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:998 [inline]
 alloc_skb_with_frags+0x1c7/0xaf0 net/core/skbuff.c:5220
 sock_alloc_send_pskb+0xafd/0x10e0 net/core/sock.c:2083
 packet_alloc_skb net/packet/af_packet.c:2781 [inline]
 packet_snd net/packet/af_packet.c:2872 [inline]
 packet_sendmsg+0x661a/0x8f30 net/packet/af_packet.c:2953
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xdb9/0x11b0 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================