syzbot

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BUG: KMSAN: uninit-value in gue6_err+0x475/0xc40 net/ipv6/fou6.c:101
CPU: 1 PID: 12868 Comm: syz-executor059 Not tainted 5.0.0-rc1+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __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:600
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
 gue6_err+0x475/0xc40 net/ipv6/fou6.c:101
 __udp6_lib_err_encap_no_sk net/ipv6/udp.c:434 [inline]
 __udp6_lib_err_encap net/ipv6/udp.c:491 [inline]
 __udp6_lib_err+0x18d0/0x2590 net/ipv6/udp.c:522
 udpv6_err+0x118/0x130 net/ipv6/udp.c:607
 icmpv6_notify+0x462/0x9f0 net/ipv6/icmp.c:784
 icmpv6_rcv+0x18ac/0x3fa0 net/ipv6/icmp.c:872
 ip6_protocol_deliver_rcu+0xb5a/0x23a0 net/ipv6/ip6_input.c:394
 ip6_input_finish net/ipv6/ip6_input.c:434 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip6_input+0x2b6/0x350 net/ipv6/ip6_input.c:443
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x4e7/0x6d0 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ipv6_rcv+0x34b/0x3f0 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4973 [inline]
 __netif_receive_skb net/core/dev.c:5083 [inline]
 process_backlog+0x756/0x10e0 net/core/dev.c:5923
 napi_poll net/core/dev.c:6346 [inline]
 net_rx_action+0x78b/0x1a60 net/core/dev.c:6412
 __do_softirq+0x53f/0x93a kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1039
 </IRQ>
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x16f/0x1a0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:696 [inline]
 ip6_finish_output2+0x1d64/0x25f0 net/ipv6/ip6_output.c:121
 ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip6_output+0x5ca/0x710 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:444 [inline]
 ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:176
 ip6_send_skb+0xfa/0x390 net/ipv6/ip6_output.c:1727
 udp_v6_send_skb+0x1733/0x1d20 net/ipv6/udp.c:1169
 udpv6_sendmsg+0x424e/0x45d0 net/ipv6/udp.c:1466
 inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xdb9/0x11b0 net/socket.c:2116
 __sys_sendmmsg+0x580/0xad0 net/socket.c:2211
 __do_sys_sendmmsg net/socket.c:2240 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2237
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2237
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x446499
Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 7b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7d55111db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 0000000000446499
RDX: 00000000000004ff RSI: 00000000200092c0 RDI: 0000000000000006
RBP: 00000000006dbc30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc3c
R13: 00007ffc4397c25f R14: 00007f7d551129c0 R15: 0000000000000001

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159
 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:2754 [inline]
 __kmalloc_node_track_caller+0xe9e/0xff0 mm/slub.c:4377
 __kmalloc_reserve net/core/skbuff.c:140 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1012 [inline]
 alloc_skb_with_frags+0x1c7/0xac0 net/core/skbuff.c:5288
hrtimer: interrupt took 178636 ns
 sock_alloc_send_pskb+0xafd/0x10a0 net/core/sock.c:2091
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2108
 __ip6_append_data+0x42ed/0x5dc0 net/ipv6/ip6_output.c:1443
 ip6_append_data+0x3c2/0x650 net/ipv6/ip6_output.c:1619
 icmp6_send+0x2f5c/0x3c40 net/ipv6/icmp.c:574
 icmpv6_send+0xe5/0x110 net/ipv6/ip6_icmp.c:43
 __udp6_lib_rcv+0x277f/0x3e80 net/ipv6/udp.c:937
 udpv6_rcv+0x5c/0x70 net/ipv6/udp.c:1026
 ip6_protocol_deliver_rcu+0xb5a/0x23a0 net/ipv6/ip6_input.c:394
 ip6_input_finish net/ipv6/ip6_input.c:434 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ip6_input+0x2b6/0x350 net/ipv6/ip6_input.c:443
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x4e7/0x6d0 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ipv6_rcv+0x34b/0x3f0 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core net/core/dev.c:4973 [inline]
 __netif_receive_skb net/core/dev.c:5083 [inline]
 process_backlog+0x756/0x10e0 net/core/dev.c:5923
 napi_poll net/core/dev.c:6346 [inline]
 net_rx_action+0x78b/0x1a60 net/core/dev.c:6412
 __do_softirq+0x53f/0x93a kernel/softirq.c:293
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