=====================================================
BUG: KMSAN: uninit-value in ipv6_find_tlv+0x39c/0x410 net/ipv6/exthdrs_core.c:147
 ipv6_find_tlv+0x39c/0x410 net/ipv6/exthdrs_core.c:147
 ip6_find_1stfragopt+0x28b/0x520 net/ipv6/output_core.c:78
 ip6_fragment+0x1db/0x3e30 net/ipv6/ip6_output.c:859
 __ip6_finish_output net/ipv6/ip6_output.c:193 [inline]
 ip6_finish_output+0x9c8/0x1230 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip6_output+0x362/0x650 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:444 [inline]
 ip6_local_out+0xe9/0x140 net/ipv6/output_core.c:155
 ip6_send_skb net/ipv6/ip6_output.c:1989 [inline]
 ip6_push_pending_frames+0x1f9/0x560 net/ipv6/ip6_output.c:2009
 rawv6_push_pending_frames+0xbd0/0xe20 net/ipv6/raw.c:583
 rawv6_sendmsg+0x2959/0x2e50 net/ipv6/raw.c:926
 inet_sendmsg+0x105/0x190 net/ipv4/af_inet.c:825
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 sock_write_iter+0x4b0/0x660 net/socket.c:1138
 call_write_iter include/linux/fs.h:1851 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x834/0x1580 fs/read_write.c:584
 ksys_write+0x21f/0x4f0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x93/0xd0 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at:
 slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774
 slab_alloc_node mm/slub.c:3452 [inline]
 __kmem_cache_alloc_node+0x518/0x920 mm/slub.c:3491
 __do_kmalloc_node mm/slab_common.c:966 [inline]
 __kmalloc_node_track_caller+0x118/0x3c0 mm/slab_common.c:987
 kmalloc_reserve+0x248/0x470 net/core/skbuff.c:537
 __alloc_skb+0x3a7/0x850 net/core/skbuff.c:606
 alloc_skb include/linux/skbuff.h:1277 [inline]
 alloc_skb_with_frags+0xbd/0xbb0 net/core/skbuff.c:6318
 sock_alloc_send_pskb+0xaad/0xc30 net/core/sock.c:2734
 sock_alloc_send_skb include/net/sock.h:1860 [inline]
 __ip6_append_data+0x5120/0x6c70 net/ipv6/ip6_output.c:1691
 ip6_append_data+0x432/0x5a0 net/ipv6/ip6_output.c:1867
 rawv6_sendmsg+0x285d/0x2e50 net/ipv6/raw.c:919
 inet_sendmsg+0x105/0x190 net/ipv4/af_inet.c:825
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 sock_write_iter+0x4b0/0x660 net/socket.c:1138
 call_write_iter include/linux/fs.h:1851 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x834/0x1580 fs/read_write.c:584
 ksys_write+0x21f/0x4f0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x93/0xd0 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CPU: 1 PID: 3216 Comm: syz-executor.0 Not tainted 6.3.0-rc7-syzkaller-g0255004d2a8e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
=====================================================