==================================================================
BUG: KMSAN: uninit-value in ipv6_ext_hdr net/ipv6/exthdrs_core.c:17 [inline]
BUG: KMSAN: uninit-value in ipv6_skip_exthdr+0x156/0x910 net/ipv6/exthdrs_core.c:78
CPU: 1 PID: 12338 Comm: syz-executor5 Not tainted 4.18.0-rc4+ #23
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+0x185/0x1e0 lib/dump_stack.c:113
 kmsan_report+0x195/0x2c0 mm/kmsan/kmsan.c:990
 __msan_warning_32+0x7d/0xe0 mm/kmsan/kmsan_instr.c:640
 ipv6_ext_hdr net/ipv6/exthdrs_core.c:17 [inline]
 ipv6_skip_exthdr+0x156/0x910 net/ipv6/exthdrs_core.c:78
 ipv6_get_l4proto+0x1be/0x2f0 net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c:83
 nf_conntrack_in+0x54a/0x2070 net/netfilter/nf_conntrack_core.c:1388
 ipv6_conntrack_local+0xc3/0xf0 net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c:179
 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
 nf_hook_slow+0x15d/0x3e0 net/netfilter/core.c:511
 nf_hook include/linux/netfilter.h:242 [inline]
 NF_HOOK include/linux/netfilter.h:285 [inline]
 rawv6_send_hdrinc net/ipv6/raw.c:678 [inline]
 rawv6_sendmsg+0x4d06/0x5410 net/ipv6/raw.c:924
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg net/socket.c:651 [inline]
 sock_write_iter+0x408/0x4d0 net/socket.c:920
 call_write_iter include/linux/fs.h:1793 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x87e/0xb90 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1cf/0x400 fs/read_write.c:607
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455e29
Code: 1d ba 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fdd3be08c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdd3be096d4 RCX: 0000000000455e29
RDX: 000000000000fdd3 RSI: 0000000020000080 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c05b2 R14: 00000000004d4660 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:271 [inline]
 kmsan_internal_chain_origin+0x13c/0x240 mm/kmsan/kmsan.c:581
 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:425
 __msan_memcpy+0xe7/0x150 mm/kmsan/kmsan_instr.c:432
 skb_copy_from_linear_data_offset include/linux/skbuff.h:3385 [inline]
 skb_copy_bits+0x1f9/0xd80 net/core/skbuff.c:2038
 ipv6_get_l4proto+0x105/0x2f0 net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c:78
 nf_conntrack_in+0x54a/0x2070 net/netfilter/nf_conntrack_core.c:1388
 ipv6_conntrack_local+0xc3/0xf0 net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c:179
 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
 nf_hook_slow+0x15d/0x3e0 net/netfilter/core.c:511
 nf_hook include/linux/netfilter.h:242 [inline]
 NF_HOOK include/linux/netfilter.h:285 [inline]
 rawv6_send_hdrinc net/ipv6/raw.c:678 [inline]
 rawv6_sendmsg+0x4d06/0x5410 net/ipv6/raw.c:924
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg net/socket.c:651 [inline]
 sock_write_iter+0x408/0x4d0 net/socket.c:920
 call_write_iter include/linux/fs.h:1793 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x87e/0xb90 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1cf/0x400 fs/read_write.c:607
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:271 [inline]
 kmsan_internal_chain_origin+0x13c/0x240 mm/kmsan/kmsan.c:581
 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:425
 kmsan_memmove_origins+0x9/0x10 mm/kmsan/kmsan.c:480
 __msan_memmove+0xe7/0x150 mm/kmsan/kmsan_instr.c:381
 nf_ct_frag6_reasm net/ipv6/netfilter/nf_conntrack_reasm.c:432 [inline]
 nf_ct_frag6_gather+0x436a/0x5870 net/ipv6/netfilter/nf_conntrack_reasm.c:586
 ipv6_defrag+0x501/0x5c0 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:71
 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
 nf_hook_slow+0x15d/0x3e0 net/netfilter/core.c:511
 nf_hook include/linux/netfilter.h:242 [inline]
 NF_HOOK include/linux/netfilter.h:285 [inline]
 rawv6_send_hdrinc net/ipv6/raw.c:678 [inline]
 rawv6_sendmsg+0x4d06/0x5410 net/ipv6/raw.c:924
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg net/socket.c:651 [inline]
 sock_write_iter+0x408/0x4d0 net/socket.c:920
 call_write_iter include/linux/fs.h:1793 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x87e/0xb90 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1cf/0x400 fs/read_write.c:607
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
 kmsan_internal_poison_shadow+0xc8/0x1d0 mm/kmsan/kmsan.c:181
 kmsan_kmalloc_large+0x7c/0xe0 mm/kmsan/kmsan_hooks.c:128
 kmalloc_large_node_hook mm/slub.c:1352 [inline]
 kmalloc_large_node mm/slub.c:3799 [inline]
 __kmalloc_node_track_caller+0xf53/0x11d0 mm/slub.c:4339
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:988 [inline]
 alloc_skb_with_frags+0x1e6/0xb80 net/core/skbuff.c:5271
 sock_alloc_send_pskb+0xb59/0x11e0 net/core/sock.c:2095
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2112
 rawv6_send_hdrinc net/ipv6/raw.c:643 [inline]
 rawv6_sendmsg+0x2d5f/0x5410 net/ipv6/raw.c:924
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg net/socket.c:651 [inline]
 sock_write_iter+0x408/0x4d0 net/socket.c:920
 call_write_iter include/linux/fs.h:1793 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x87e/0xb90 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1cf/0x400 fs/read_write.c:607
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================