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BUG: KMSAN: uninit-value in ip6_parse_tlv+0x8b8/0xcb0 net/ipv6/exthdrs.c:169
CPU: 1 PID: 22807 Comm: syz-executor.2 Not tainted 5.8.0-rc5-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+0x1df/0x240 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_parse_hopopts+0x493/0x7c0 net/ipv6/exthdrs.c:1043
 ip6_rcv_core+0x1b08/0x1ff0 net/ipv6/ip6_input.c:278
 ipv6_rcv+0xe3/0x710 net/ipv6/ip6_input.c:304
 __netif_receive_skb_one_core net/core/dev.c:5281 [inline]
 __netif_receive_skb net/core/dev.c:5395 [inline]
 process_backlog+0x72c/0x14e0 net/core/dev.c:6239
 napi_poll net/core/dev.c:6684 [inline]
 net_rx_action+0x746/0x1aa0 net/core/dev.c:6752
 __do_softirq+0x311/0x83d kernel/softirq.c:293
 asm_call_on_stack+0x12/0x20 arch/x86/entry/entry_64.S:711
 </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 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:723 [inline]
 ip6_finish_output2+0x2111/0x2620 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:443 [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:814
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x10e2/0x1400 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmmsg+0x876/0xd80 net/socket.c:2489
 __compat_sys_sendmmsg net/compat.c:480 [inline]
 __do_compat_sys_sendmmsg net/compat.c:487 [inline]
 __se_compat_sys_sendmmsg+0xcd/0xf0 net/compat.c:484
 __ia32_compat_sys_sendmmsg+0x56/0x70 net/compat.c:484
 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline]
 __do_fast_syscall_32+0x2aa/0x400 arch/x86/entry/common.c:477
 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7fd0549
Code: Bad RIP value.
RSP: 002b:00000000f5dcb0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000159
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000480
RDX: 00000000000002e9 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

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:2839 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4478
 __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]
 __ip6_append_data+0x48c3/0x6320 net/ipv6/ip6_output.c:1588
 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:814
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x10e2/0x1400 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmmsg+0x876/0xd80 net/socket.c:2489
 __compat_sys_sendmmsg net/compat.c:480 [inline]
 __do_compat_sys_sendmmsg net/compat.c:487 [inline]
 __se_compat_sys_sendmmsg+0xcd/0xf0 net/compat.c:484
 __ia32_compat_sys_sendmmsg+0x56/0x70 net/compat.c:484
 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline]
 __do_fast_syscall_32+0x2aa/0x400 arch/x86/entry/common.c:477
 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
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