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BUG: KMSAN: uninit-value in ip6_parse_tlv+0x8b8/0xcb0 net/ipv6/exthdrs.c:169
CPU: 1 PID: 22853 Comm: syz-executor.5 Not tainted 5.7.0-rc4-syzkaller #0
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+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 ip6_parse_tlv+0x8b8/0xcb0 net/ipv6/exthdrs.c:169
 ipv6_destopt_rcv+0x5bf/0xdd0 net/ipv6/exthdrs.c:308
 ip6_protocol_deliver_rcu+0x181b/0x22c0 net/ipv6/ip6_input.c:433
 ip6_input_finish net/ipv6/ip6_input.c:474 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:483
 dst_input include/net/dst.h:441 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:307
 __netif_receive_skb_one_core net/core/dev.c:5188 [inline]
 __netif_receive_skb net/core/dev.c:5302 [inline]
 process_backlog+0xa41/0x1410 net/core/dev.c:6134
 napi_poll net/core/dev.c:6572 [inline]
 net_rx_action+0x786/0x1aa0 net/core/dev.c:6640
 __do_softirq+0x311/0x83d kernel/softirq.c:293
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1091
 </IRQ>
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:690 [inline]
 ip6_finish_output2+0x2113/0x2640 net/ipv6/ip6_output.c:118
 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:143
 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:435 [inline]
 ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179
 ip6_send_skb net/ipv6/ip6_output.c:1865 [inline]
 ip6_push_pending_frames+0x213/0x4f0 net/ipv6/ip6_output.c:1885
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x4233/0x5c30 net/ipv6/raw.c:956
 inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x1056/0x1350 net/socket.c:2362
 ___sys_sendmsg net/socket.c:2416 [inline]
 __sys_sendmmsg+0x5fe/0xd60 net/socket.c:2506
 __do_sys_sendmmsg net/socket.c:2535 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2532
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2532
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f8209913c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004fd760 RCX: 000000000045cb29
RDX: 00000000000002e9 RSI: 0000000020000480 RDI: 0000000000000006
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000903 R14: 00000000004cbe13 R15: 00007f82099146d4

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2802 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4436
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1083 [inline]
 alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5772
 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2265
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2282
 __ip6_append_data+0x4784/0x63e0 net/ipv6/ip6_output.c:1581
 ip6_append_data+0x3cb/0x660 net/ipv6/ip6_output.c:1757
 rawv6_sendmsg+0x32bb/0x5c30 net/ipv6/raw.c:949
 inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x1056/0x1350 net/socket.c:2362
 ___sys_sendmsg net/socket.c:2416 [inline]
 __sys_sendmmsg+0x5fe/0xd60 net/socket.c:2506
 __do_sys_sendmmsg net/socket.c:2535 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2532
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2532
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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