KMSAN: uninit-value in dccp_invalid

KMSAN: uninit-value in dccp_invalid_packet
Status: upstream: reported C repro on 2018/04/19 17:06
Reported-by: syzbot+00763607efc31f91b276@syzkaller.appspotmail.com
First crash: 1065d, last: 1051d

Sample crash report:

IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
==================================================================
BUG: KMSAN: uninit-value in dccp_invalid_packet+0x3b8/0xf50 net/dccp/ipv4.c:716
CPU: 1 PID: 3572 Comm: syzkaller338124 Not tainted 4.16.0+ #82
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
 dccp_invalid_packet+0x3b8/0xf50 net/dccp/ipv4.c:716
 dccp_v4_rcv+0xf7/0x2630 net/dccp/ipv4.c:778
 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
 </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]
 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]
 SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747
 SyS_sendto+0x8a/0xb0 net/socket.c:1715
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x441709
RSP: 002b:00007ffffde4d688 EFLAGS: 00000217 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000000001b RCX: 0000000000441709
RDX: 0000000000000030 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00000000004a3318 R08: 0000000020000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000217 R12: 00007ffffde4d768
R13: 0000000000402490 R14: 0000000000000000 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]
 dccp_invalid_packet+0x352/0xf50 net/dccp/ipv4.c:708
 dccp_v4_rcv+0xf7/0x2630 net/dccp/ipv4.c:778
 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
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_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
 sk_page_frag_refill+0xa4/0x340 net/core/sock.c:2228
 __ip_append_data+0x107e/0x3d10 net/ipv4/ip_output.c:1057
 ip_append_data+0x2fb/0x440 net/ipv4/ip_output.c:1170
 raw_sendmsg+0x287b/0x3ed0 net/ipv4/raw.c:678
 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]
 SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747
 SyS_sendto+0x8a/0xb0 net/socket.c:1715
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
==================================================================

Crashes (24):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kmsan-gce	2018/04/10 08:42	https://github.com/google/kmsan.git master	e2ab7e8a	b9f65507	.config	log	report	syz	C
ci-upstream-kmsan-gce	2018/04/21 02:50	https://github.com/google/kmsan.git master	48c6a2b0	ca03d688	.config	log	report
ci-upstream-kmsan-gce	2018/04/20 16:43	https://github.com/google/kmsan.git master	48c6a2b0	cc402841	.config	log	report
ci-upstream-kmsan-gce	2018/04/20 16:43	https://github.com/google/kmsan.git master	48c6a2b0	cc402841	.config	log	report
ci-upstream-kmsan-gce	2018/04/20 16:42	https://github.com/google/kmsan.git master	48c6a2b0	cc402841	.config	log	report
ci-upstream-kmsan-gce	2018/04/20 03:57	https://github.com/google/kmsan.git master	48c6a2b0	eae05cb0	.config	log	report
ci-upstream-kmsan-gce	2018/04/19 13:04	https://github.com/google/kmsan.git master	48c6a2b0	3642839c	.config	log	report
ci-upstream-kmsan-gce	2018/04/19 11:03	https://github.com/google/kmsan.git master	48c6a2b0	d1b2ef69	.config	log	report
ci-upstream-kmsan-gce	2018/04/19 09:49	https://github.com/google/kmsan.git master	48c6a2b0	d1b2ef69	.config	log	report
ci-upstream-kmsan-gce	2018/04/18 21:03	https://github.com/google/kmsan.git master	48c6a2b0	829f0234	.config	log	report
ci-upstream-kmsan-gce	2018/04/18 20:20	https://github.com/google/kmsan.git master	48c6a2b0	829f0234	.config	log	report
ci-upstream-kmsan-gce	2018/04/18 06:55	https://github.com/google/kmsan.git master	48c6a2b0	b80fd3b5	.config	log	report
ci-upstream-kmsan-gce	2018/04/17 06:48	https://github.com/google/kmsan.git master	48c6a2b0	b80fd3b5	.config	log	report
ci-upstream-kmsan-gce	2018/04/17 01:10	https://github.com/google/kmsan.git master	48c6a2b0	b80fd3b5	.config	log	report
ci-upstream-kmsan-gce	2018/04/15 10:49	https://github.com/google/kmsan.git master	35ff515e	7a67784c	.config	log	report
ci-upstream-kmsan-gce	2018/04/10 08:15	https://github.com/google/kmsan.git master	e2ab7e8a	b9f65507	.config	log	report
ci-upstream-kmsan-gce	2018/04/09 18:48	https://github.com/google/kmsan.git master	e2ab7e8a	f13fb445	.config	log	report
ci-upstream-kmsan-gce	2018/04/09 14:48	https://github.com/google/kmsan.git master	e2ab7e8a	f13fb445	.config	log	report
ci-upstream-kmsan-gce	2018/04/09 13:49	https://github.com/google/kmsan.git master	e2ab7e8a	f13fb445	.config	log	report
ci-upstream-kmsan-gce	2018/04/07 07:56	https://github.com/google/kmsan.git master	e2ab7e8a	d613535f	.config	log	report
ci-upstream-kmsan-gce	2018/04/07 06:38	https://github.com/google/kmsan.git master	e2ab7e8a	d613535f	.config	log	report
ci-upstream-kmsan-gce	2018/04/07 06:29	https://github.com/google/kmsan.git master	e2ab7e8a	d613535f	.config	log	report
ci-upstream-kmsan-gce	2018/04/07 06:00	https://github.com/google/kmsan.git master	e2ab7e8a	d613535f	.config	log	report
ci-upstream-kmsan-gce	2018/04/07 05:52	https://github.com/google/kmsan.git master	e2ab7e8a	d613535f	.config	log	report