==================================================================
BUG: KMSAN: uninit-value in memcmp+0x119/0x180 lib/string.c:861
CPU: 1 PID: 5579 Comm: syz-executor5 Not tainted 4.16.0+ #83
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 memcmp+0x119/0x180 lib/string.c:861
 tcp_v6_inbound_md5_hash+0x5e3/0x900 net/ipv6/tcp_ipv6.c:706
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1040
 </IRQ>
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x114/0x140 kernel/softirq.c:182
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:726 [inline]
 ip6_finish_output2+0x1b6c/0x1f20 net/ipv6/ip6_output.c:121
 ip6_finish_output+0xb3f/0xc00 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:277 [inline]
 ip6_output+0x597/0x6c0 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:443 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_xmit+0x1e3c/0x2120 net/ipv6/ip6_output.c:277
 inet6_csk_xmit+0x35b/0x440 net/ipv6/inet6_connection_sock.c:139
 tcp_transmit_skb+0x38be/0x51f0 net/ipv4/tcp_output.c:1176
 tcp_write_xmit+0x4311/0xb920 net/ipv4/tcp_output.c:2394
 tcp_push_one+0x195/0x230 net/ipv4/tcp_output.c:2581
 do_tcp_sendpages+0x31a8/0x3b50 net/ipv4/tcp.c:1024
 tcp_sendpage_locked net/ipv4/tcp.c:1071 [inline]
 tcp_sendpage+0x3d2/0x430 net/ipv4/tcp.c:1081
 inet_sendpage+0x4ea/0x8c0 net/ipv4/af_inet.c:781
 kernel_sendpage net/socket.c:3234 [inline]
 sock_sendpage+0x1de/0x2c0 net/socket.c:855
 pipe_to_sendpage+0x31b/0x430 fs/splice.c:451
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x49a/0xf30 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 generic_splice_sendpage+0x1c6/0x2a0 fs/splice.c:832
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x19b/0x200 fs/splice.c:1018
 splice_direct_to_actor+0x764/0x1040 fs/splice.c:973
 do_splice_direct+0x335/0x540 fs/splice.c:1061
 do_sendfile+0x1067/0x1e40 fs/read_write.c:1413
 SYSC_sendfile64+0x1b3/0x300 fs/read_write.c:1468
 SyS_sendfile64+0x64/0x90 fs/read_write.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455259
RSP: 002b:00007f564f14dc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f564f14e6d4 RCX: 0000000000455259
RDX: 000000002053cffc RSI: 0000000000000015 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004c6 R14: 00000000006fa330 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 md5_transform+0x230b/0x2390 crypto/md5.c:137
 md5_transform_helper crypto/md5.c:146 [inline]
 md5_update+0x3a5/0x590 crypto/md5.c:184
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 tcp_md5_hash_skb_data+0x96a/0xcd0 net/ipv4/tcp.c:3485
 tcp_v6_md5_hash_skb+0x6f7/0x9c0 net/ipv6/tcp_ipv6.c:653
 tcp_v6_inbound_md5_hash+0x375/0x900 net/ipv6/tcp_ipv6.c:702
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 md5_transform+0x230b/0x2390 crypto/md5.c:137
 md5_transform_helper crypto/md5.c:146 [inline]
 md5_update+0x3a5/0x590 crypto/md5.c:184
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 tcp_md5_hash_skb_data+0x96a/0xcd0 net/ipv4/tcp.c:3485
 tcp_v6_md5_hash_skb+0x6f7/0x9c0 net/ipv6/tcp_ipv6.c:653
 tcp_v6_inbound_md5_hash+0x375/0x900 net/ipv6/tcp_ipv6.c:702
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 md5_transform+0x230b/0x2390 crypto/md5.c:137
 md5_transform_helper crypto/md5.c:146 [inline]
 md5_update+0x3a5/0x590 crypto/md5.c:184
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 tcp_md5_hash_skb_data+0x96a/0xcd0 net/ipv4/tcp.c:3485
 tcp_v6_md5_hash_skb+0x6f7/0x9c0 net/ipv6/tcp_ipv6.c:653
 tcp_v6_inbound_md5_hash+0x375/0x900 net/ipv6/tcp_ipv6.c:702
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 md5_transform+0x230b/0x2390 crypto/md5.c:137
 md5_transform_helper crypto/md5.c:146 [inline]
 md5_update+0x3a5/0x590 crypto/md5.c:184
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 tcp_md5_hash_skb_data+0x96a/0xcd0 net/ipv4/tcp.c:3485
 tcp_v6_md5_hash_skb+0x6f7/0x9c0 net/ipv6/tcp_ipv6.c:653
 tcp_v6_inbound_md5_hash+0x375/0x900 net/ipv6/tcp_ipv6.c:702
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 md5_transform+0x230b/0x2390 crypto/md5.c:137
 md5_transform_helper crypto/md5.c:146 [inline]
 md5_update+0x3a5/0x590 crypto/md5.c:184
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 tcp_md5_hash_skb_data+0x96a/0xcd0 net/ipv4/tcp.c:3485
 tcp_v6_md5_hash_skb+0x6f7/0x9c0 net/ipv6/tcp_ipv6.c:653
 tcp_v6_inbound_md5_hash+0x375/0x900 net/ipv6/tcp_ipv6.c:702
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
 md5_transform+0x230b/0x2390 crypto/md5.c:137
 md5_transform_helper crypto/md5.c:146 [inline]
 md5_update+0x233/0x590 crypto/md5.c:178
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 tcp_md5_hash_skb_data+0x96a/0xcd0 net/ipv4/tcp.c:3485
 tcp_v6_md5_hash_skb+0x6f7/0x9c0 net/ipv6/tcp_ipv6.c:653
 tcp_v6_inbound_md5_hash+0x375/0x900 net/ipv6/tcp_ipv6.c:702
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:526
 __msan_memcpy+0x19f/0x1f0 mm/kmsan/kmsan_instr.c:470
 md5_update+0x207/0x590 crypto/md5.c:175
 crypto_shash_update crypto/shash.c:117 [inline]
 shash_ahash_update crypto/shash.c:239 [inline]
 shash_async_update+0x290/0x360 crypto/shash.c:247
 crypto_ahash_update include/crypto/hash.h:522 [inline]
 tcp_md5_hash_skb_data+0x96a/0xcd0 net/ipv4/tcp.c:3485
 tcp_v6_md5_hash_skb+0x6f7/0x9c0 net/ipv6/tcp_ipv6.c:653
 tcp_v6_inbound_md5_hash+0x375/0x900 net/ipv6/tcp_ipv6.c:702
 tcp_v6_rcv+0x4b03/0x62c0 net/ipv6/tcp_ipv6.c:1498
 ip6_input_finish+0xa62/0x2110 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:71 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x20ec/0x26d0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_alloc_meta_for_pages+0x161/0x3a0 mm/kmsan/kmsan.c:814
 kmsan_alloc_page+0x82/0xe0 mm/kmsan/kmsan.c:868
 __alloc_pages_nodemask+0xf5b/0x5dc0 mm/page_alloc.c:4283
 alloc_pages_vma+0xcc8/0x1800 mm/mempolicy.c:2019
 shmem_alloc_page mm/shmem.c:1471 [inline]
 shmem_alloc_and_acct_page+0x6d5/0x1000 mm/shmem.c:1496
 shmem_getpage_gfp+0x35db/0x5770 mm/shmem.c:1771
 shmem_getpage mm/shmem.c:131 [inline]
 shmem_file_read_iter+0x508/0x1180 mm/shmem.c:2456
 call_read_iter include/linux/fs.h:1776 [inline]
 generic_file_splice_read+0x4e8/0x830 fs/splice.c:307
 do_splice_to fs/splice.c:880 [inline]
 splice_direct_to_actor+0x4c6/0x1040 fs/splice.c:952
 do_splice_direct+0x335/0x540 fs/splice.c:1061
 do_sendfile+0x1067/0x1e40 fs/read_write.c:1413
 SYSC_sendfile64+0x1b3/0x300 fs/read_write.c:1468
 SyS_sendfile64+0x64/0x90 fs/read_write.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
==================================================================