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BUG: KMSAN: uninit-value in ipv6_find_tlv+0x370/0x3c0 net/ipv6/exthdrs_core.c:147
CPU: 0 PID: 19738 Comm: syz-executor.0 Not tainted 5.4.0-rc8-syzkaller #0
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+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108
 __msan_warning+0x64/0xc0 mm/kmsan/kmsan_instr.c:245
 ipv6_find_tlv+0x370/0x3c0 net/ipv6/exthdrs_core.c:147
 ip6_find_1stfragopt+0x2b6/0x500 net/ipv6/output_core.c:102
 ip6_fragment+0x290/0x3890 net/ipv6/ip6_output.c:776
 __ip6_finish_output+0x753/0x8f0 net/ipv6/ip6_output.c:140
 ip6_finish_output+0x2db/0x420 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179
 ip6_send_skb net/ipv6/ip6_output.c:1795 [inline]
 ip6_push_pending_frames+0x215/0x4f0 net/ipv6/ip6_output.c:1815
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x4125/0x5a20 net/ipv6/raw.c:956
 inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 ___sys_sendmsg+0x12c4/0x1590 net/socket.c:2311
 __sys_sendmsg net/socket.c:2356 [inline]
 __do_sys_sendmsg net/socket.c:2365 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2363
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2363
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45a649
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007efe1bf19c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a649
RDX: 0000000000000000 RSI: 0000000020000a40 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007efe1bf1a6d4
R13: 00000000004c8656 R14: 00000000004ded48 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:149 [inline]
 kmsan_internal_poison_shadow+0x5c/0x110 mm/kmsan/kmsan.c:132
 kmsan_slab_alloc+0x97/0x100 mm/kmsan/kmsan_hooks.c:86
 slab_alloc_node mm/slub.c:2773 [inline]
 __kmalloc_node_track_caller+0xe27/0x11a0 mm/slub.c:4381
 __kmalloc_reserve net/core/skbuff.c:141 [inline]
 pskb_expand_head+0x21c/0x19f0 net/core/skbuff.c:1628
 __pskb_pull_tail+0x178/0x1de0 net/core/skbuff.c:2059
 pskb_may_pull include/linux/skbuff.h:2286 [inline]
 nf_ct_frag6_gather+0xf6b/0x35a0 net/ipv6/netfilter/nf_conntrack_reasm.c:457
 ipv6_defrag+0x545/0x660 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:66
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_slow+0x18b/0x3f0 net/netfilter/core.c:512
 nf_hook include/linux/netfilter.h:260 [inline]
 __ip6_local_out+0x56d/0x750 net/ipv6/output_core.c:167
 ip6_local_out+0xa4/0x1d0 net/ipv6/output_core.c:177
 ip6_send_skb net/ipv6/ip6_output.c:1795 [inline]
 ip6_push_pending_frames+0x215/0x4f0 net/ipv6/ip6_output.c:1815
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x4125/0x5a20 net/ipv6/raw.c:956
 inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 ___sys_sendmsg+0x12c4/0x1590 net/socket.c:2311
 __sys_sendmsg net/socket.c:2356 [inline]
 __do_sys_sendmsg net/socket.c:2365 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2363
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2363
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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