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BUG: KMSAN: uninit-value in ip6_parse_tlv+0xa37/0xf80 net/ipv6/exthdrs.c:156
CPU: 1 PID: 29895 Comm: syz-executor.3 Not tainted 5.9.0-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+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:201
 ip6_parse_tlv+0xa37/0xf80 net/ipv6/exthdrs.c:156
 ipv6_parse_hopopts+0x540/0x860 net/ipv6/exthdrs.c:1043
 ip6_rcv_core+0x1e97/0x2390 net/ipv6/ip6_input.c:278
 ipv6_rcv+0xeb/0x460 net/ipv6/ip6_input.c:304
 __netif_receive_skb_one_core net/core/dev.c:5286 [inline]
 __netif_receive_skb+0x265/0x670 net/core/dev.c:5400
 process_backlog+0x50d/0xba0 net/core/dev.c:6242
 napi_poll+0x443/0x1100 net/core/dev.c:6688
 net_rx_action+0x35c/0xd40 net/core/dev.c:6758
 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:299
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:23 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline]
 do_softirq_own_stack+0x7c/0xa0 arch/x86/kernel/irq_64.c:77
 do_softirq+0xed/0x150 kernel/softirq.c:344
 netif_rx_ni+0x21b/0x3c0 net/core/dev.c:4835
 dev_loopback_xmit+0x64c/0x730 net/core/dev.c:3851
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_finish_output2+0x274a/0x2a70 net/ipv6/ip6_output.c:81
 __ip6_finish_output+0x9c0/0xa90 net/ipv6/ip6_output.c:143
 ip6_finish_output+0x14b/0x4b0 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:290 [inline]
 ip6_output+0x68d/0x7f0 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:443 [inline]
 ip6_local_out+0x17b/0x1e0 net/ipv6/output_core.c:179
 ip6_send_skb net/ipv6/ip6_output.c:1867 [inline]
 ip6_push_pending_frames+0x252/0x5b0 net/ipv6/ip6_output.c:1887
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x42fe/0x4740 net/ipv6/raw.c:956
 inet_sendmsg+0x15b/0x1d0 net/ipv4/af_inet.c:817
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc82/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmmsg+0xa05/0xf70 net/socket.c:2497
 __do_sys_sendmmsg net/socket.c:2526 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2523
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2523
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de29
Code: 0d b4 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f55a12b5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000027fc0 RCX: 000000000045de29
RDX: 0000000000000001 RSI: 0000000020004040 RDI: 0000000000000003
RBP: 000000000118bf68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 000000000169fb7f R14: 00007f55a12b69c0 R15: 000000000118bf2c

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:143 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:126
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2907 [inline]
 __kmalloc_node_track_caller+0x9aa/0x12f0 mm/slub.c:4511
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x35f/0xb30 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 __ip6_append_data+0x5168/0x71b0 net/ipv6/ip6_output.c:1590
 ip6_append_data+0x44b/0x6e0 net/ipv6/ip6_output.c:1759
 rawv6_sendmsg+0x2cfe/0x4740 net/ipv6/raw.c:949
 inet_sendmsg+0x15b/0x1d0 net/ipv4/af_inet.c:817
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc82/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmmsg+0xa05/0xf70 net/socket.c:2497
 __do_sys_sendmmsg net/socket.c:2526 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2523
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2523
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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