=====================================================
BUG: KMSAN: uninit-value in ipv6_find_tlv+0x35d/0x3b0 net/ipv6/exthdrs_core.c:147
CPU: 0 PID: 5466 Comm: syz-executor.2 Not tainted 5.6.0-rc2-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+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 ipv6_find_tlv+0x35d/0x3b0 net/ipv6/exthdrs_core.c:147
 ip6_find_1stfragopt+0x2a6/0x500 net/ipv6/output_core.c:102
 ip6_fragment+0x2b2/0x3950 net/ipv6/ip6_output.c:776
 __ip6_finish_output+0x73a/0x8e0 net/ipv6/ip6_output.c:140
 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x60a/0x770 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+0x213/0x4f0 net/ipv6/ip6_output.c:1815
 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_sendto+0xaba/0xc50 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:2006
 __x64_sys_sendto+0x6e/0x90 net/socket.c:2006
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c429
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:00007f21ae955c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f21ae9566d4 RCX: 000000000045c429
RDX: 000000000000ffd0 RSI: 0000000020000280 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: fffffffffffffdd5
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a04 R14: 00000000004cc770 R15: 000000000076bf2c

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:82
 slab_alloc_node mm/slub.c:2793 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 pskb_expand_head+0x20b/0x1b00 net/core/skbuff.c:1629
 __pskb_pull_tail+0x17a/0x1dd0 net/core/skbuff.c:2060
 pskb_may_pull include/linux/skbuff.h:2307 [inline]
 nf_ct_frag6_gather+0xf79/0x35f0 net/ipv6/netfilter/nf_conntrack_reasm.c:457
 ipv6_defrag+0x523/0x640 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:66
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_slow+0x16e/0x400 net/netfilter/core.c:512
 nf_hook include/linux/netfilter.h:262 [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+0x213/0x4f0 net/ipv6/ip6_output.c:1815
 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_sendto+0xaba/0xc50 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:2006
 __x64_sys_sendto+0x6e/0x90 net/socket.c:2006
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
=====================================================