================================================================== BUG: KMSAN: uninit-value in tcp_v4_rcv+0xc5f/0x6750 net/ipv4/tcp_ipv4.c:1648 CPU: 1 PID: 7006 Comm: syz-executor7 Not tainted 4.16.0+ #84 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __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 tcp_v4_rcv+0xc5f/0x6750 net/ipv4/tcp_ipv4.c:1648 ip_local_deliver_finish+0x6ed/0xd40 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:288 [inline] ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:449 [inline] ip_rcv_finish+0x1253/0x16d0 net/ipv4/ip_input.c:397 NF_HOOK include/linux/netfilter.h:288 [inline] ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493 __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 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] ip_finish_output2+0x124e/0x1380 net/ipv4/ip_output.c:231 ip_finish_output+0xcb0/0xff0 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:277 [inline] ip_output+0x502/0x5c0 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:124 [inline] ip_send_skb+0x5f3/0x820 net/ipv4/ip_output.c:1414 ip_push_pending_frames+0x105/0x170 net/ipv4/ip_output.c:1434 raw_sendmsg+0x2960/0x3ed0 net/ipv4/raw.c:684 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] sock_write_iter+0x3b9/0x470 net/socket.c:909 call_write_iter include/linux/fs.h:1782 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x719/0x910 fs/read_write.c:482 ================================================================== vfs_write+0x463/0x8d0 fs/read_write.c:544 SYSC_write+0x172/0x360 fs/read_write.c:589 SyS_write+0x55/0x80 fs/read_write.c:581 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x455389 RSP: 002b:00007f4788e2cc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f4788e2d6d4 RCX: 0000000000455389 RDX: 0000000000000014 RSI: 0000000020000240 RDI: 0000000000000013 WARNING: memcpy-param-overlap in generic_perform_write+0x4c6/0x990 mm/filemap.c:3146 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000006c6 R14: 00000000006fd330 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 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:526 __msan_memcpy+0x19f/0x1f0 mm/kmsan/kmsan_instr.c:470 skb_copy_bits+0x63a/0xdb0 net/core/skbuff.c:2046 __pskb_pull_tail+0x483/0x22e0 net/core/skbuff.c:1883 pskb_may_pull include/linux/skbuff.h:2112 [inline] tcp_v4_rcv+0xc09/0x6750 net/ipv4/tcp_ipv4.c:1643 __msan_memcpy(ffff88015e58a001, ffff88015e58a000, 4095) ip_local_deliver_finish+0x6ed/0xd40 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:288 [inline] ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:449 [inline] ip_rcv_finish+0x1253/0x16d0 net/ipv4/ip_input.c:397 NF_HOOK include/linux/netfilter.h:288 [inline] ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562 CPU: 0 PID: 7024 Comm: syz-executor3 Not tainted 4.16.0+ #84 __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 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 __do_softirq+0x56d/0x93d kernel/softirq.c:285 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_alloc_meta_for_pages+0x161/0x3a0 mm/kmsan/kmsan.c:814 Call Trace: kmsan_alloc_page+0x82/0xe0 mm/kmsan/kmsan.c:868 __alloc_pages_nodemask+0xf5b/0x5dc0 mm/page_alloc.c:4283 __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 alloc_pages_current+0x6b5/0x970 mm/mempolicy.c:2055 alloc_pages include/linux/gfp.h:494 [inline] skb_page_frag_refill+0x3ba/0x5e0 net/core/sock.c:2208 __msan_memcpy+0x90/0x1f0 mm/kmsan/kmsan_instr.c:433 sk_page_frag_refill+0xa4/0x340 net/core/sock.c:2228 __ip_append_data+0x107e/0x3d10 net/ipv4/ip_output.c:1057 memcpy_from_page lib/iov_iter.c:459 [inline] iov_iter_copy_from_user_atomic+0xb04/0x17d0 lib/iov_iter.c:792 ip_append_data+0x2fb/0x440 net/ipv4/ip_output.c:1170 raw_sendmsg+0x287b/0x3ed0 net/ipv4/raw.c:678 generic_perform_write+0x4c6/0x990 mm/filemap.c:3146 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] sock_write_iter+0x3b9/0x470 net/socket.c:909 call_write_iter include/linux/fs.h:1782 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x719/0x910 fs/read_write.c:482 vfs_write+0x463/0x8d0 fs/read_write.c:544 __generic_file_write_iter+0x43b/0x990 mm/filemap.c:3263 SYSC_write+0x172/0x360 fs/read_write.c:589 SyS_write+0x55/0x80 fs/read_write.c:581 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 generic_file_write_iter+0x814/0xbf0 mm/filemap.c:3291 ==================================================================