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BUG: KMSAN: uninit-value in ip_rcv+0xa93/0x16a0 net/ipv4/ip_input.c:464
CPU: 1 PID: 9361 Comm: syz-executor6 Not tainted 4.17.0+ #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1368
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:634
 ip_rcv+0xa93/0x16a0 net/ipv4/ip_input.c:464
 __netif_receive_skb_core+0x47f3/0x4aa0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x766/0x1a80 net/core/dev.c:5801
 __do_softirq+0x592/0x979 kernel/softirq.c:285
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 </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:728 [inline]
 ip_finish_output2+0x136a/0x1480 net/ipv4/ip_output.c:231
 ip_finish_output+0xcbc/0x1000 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:277 [inline]
 ip_output+0x505/0x5d0 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out net/ipv4/ip_output.c:124 [inline]
 ip_queue_xmit+0x1b0f/0x1d00 net/ipv4/ip_output.c:504
 tcp_transmit_skb+0x3db5/0x5350 net/ipv4/tcp_output.c:1176
 tcp_write_xmit+0x2d81/0xb200 net/ipv4/tcp_output.c:2373
 __tcp_push_pending_frames+0x124/0x400 net/ipv4/tcp_output.c:2546
 tcp_push+0x803/0x8f0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x4eb1/0x6610 net/ipv4/tcp.c:1410
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 ___sys_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmmsg+0x490/0x850 net/socket.c:2212
 __do_sys_sendmmsg net/socket.c:2241 [inline]
 __se_sys_sendmmsg net/socket.c:2238 [inline]
 __x64_sys_sendmmsg+0x11c/0x170 net/socket.c:2238
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455ab9
RSP: 002b:00007f658f653c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f658f6546d4 RCX: 0000000000455ab9
RDX: 04000000000001b4 RSI: 00000000200010c0 RDI: 0000000000000013
RBP: 000000000072bf48 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000040400d4 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c0cd8 R14: 00000000004d0d40 R15: 0000000000000001

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:287 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:302 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:692
 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:535
 __msan_memcpy+0xda/0x130 mm/kmsan/kmsan_instr.c:427
 pskb_expand_head+0x3a6/0x1a70 net/core/skbuff.c:1470
 skb_unclone include/linux/skbuff.h:1441 [inline]
 skb_copy_ubufs+0x375/0x2650 net/core/skbuff.c:1184
 skb_orphan_frags_rx include/linux/skbuff.h:2569 [inline]
 __netif_receive_skb_core+0x48b8/0x4aa0 net/core/dev.c:4589
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x766/0x1a80 net/core/dev.c:5801
 __do_softirq+0x592/0x979 kernel/softirq.c:285

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:287 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:197
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:323
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:330
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb35/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb_fclone include/linux/skbuff.h:1030 [inline]
 sk_stream_alloc_skb+0x17c/0xcf0 net/ipv4/tcp.c:875
 tcp_sendmsg_locked+0x237e/0x6610 net/ipv4/tcp.c:1290
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 ___sys_sendmsg+0xec8/0x1320 net/socket.c:2117
 __sys_sendmmsg+0x490/0x850 net/socket.c:2212
 __do_sys_sendmmsg net/socket.c:2241 [inline]
 __se_sys_sendmmsg net/socket.c:2238 [inline]
 __x64_sys_sendmmsg+0x11c/0x170 net/socket.c:2238
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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