KMSAN: uninit-value in _decode

KMSAN: uninit-value in _decode_session6
Status: upstream: reported C repro on 2018/04/08 07:15
Reported-by: syzbot+2974b85346f85b586f4d@syzkaller.appspotmail.com
First crash: 1170d, last: 964d

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2021/03/29 16:37	19m	alaaemadhossney.ae@gmail.com		https://github.com/google/kmsan.git master	OK

Sample crash report:

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
8021q: adding VLAN 0 to HW filter on device team0
==================================================================
BUG: KMSAN: uninit-value in _decode_session6+0x6d2/0x16e0 net/ipv6/xfrm6_policy.c:151
CPU: 0 PID: 4529 Comm: syz-executor165 Not tainted 4.16.0+ #87
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:683
 _decode_session6+0x6d2/0x16e0 net/ipv6/xfrm6_policy.c:151
 __xfrm_decode_session+0x151/0x200 net/xfrm/xfrm_policy.c:2368
 xfrm_decode_session_reverse include/net/xfrm.h:1213 [inline]
 icmpv6_route_lookup net/ipv6/icmp.c:372 [inline]
 icmp6_send+0x2bf7/0x3730 net/ipv6/icmp.c:551
 icmpv6_send+0xe0/0x110 net/ipv6/ip6_icmp.c:43
 ip6_link_failure+0x8f/0x580 net/ipv6/route.c:2034
 dst_link_failure include/net/dst.h:426 [inline]
 ip6_tnl_xmit+0x1423/0x3af0 net/ipv6/ip6_tunnel.c:1215
 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1367 [inline]
 ip6_tnl_start_xmit+0x1cc0/0x1ef0 net/ipv6/ip6_tunnel.c:1390
 __netdev_start_xmit include/linux/netdevice.h:4066 [inline]
 netdev_start_xmit include/linux/netdevice.h:4075 [inline]
 xmit_one net/core/dev.c:3026 [inline]
 dev_hard_start_xmit+0x5f1/0xc70 net/core/dev.c:3042
 __dev_queue_xmit+0x27ee/0x3520 net/core/dev.c:3557
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1390
 neigh_output include/net/neighbour.h:482 [inline]
 ip6_finish_output2+0x1d01/0x2130 net/ipv6/ip6_output.c:120
 ip6_finish_output+0xae9/0xba0 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]
 ip6_local_out+0x15e/0x1d0 net/ipv6/output_core.c:176
 ip6_send_skb net/ipv6/ip6_output.c:1682 [inline]
 ip6_push_pending_frames+0x218/0x4d0 net/ipv6/ip6_output.c:1702
 rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
 rawv6_sendmsg+0x4235/0x4fb0 net/ipv6/raw.c:935
 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+0x7fb/0x9f0 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: 0033:0x4418b9
RSP: 002b:00007ffece331e68 EFLAGS: 00000217 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004418b9
RDX: 000000000000036b RSI: 0000000020000240 RDI: 0000000000000004
RBP: 00000000006cd018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004025b0
R13: 0000000000402640 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321
 slab_post_alloc_hook mm/slab.h:445 [inline]
 slab_alloc_node mm/slub.c:2737 [inline]
 __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 pskb_expand_head+0x21d/0x1a70 net/core/skbuff.c:1458
 __pskb_pull_tail+0x1d7/0x2300 net/core/skbuff.c:1878
 pskb_may_pull include/linux/skbuff.h:2112 [inline]
 ip6_tnl_parse_tlv_enc_lim+0x7f5/0xa90 net/ipv6/ip6_tunnel.c:411
 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1326 [inline]
 ip6_tnl_start_xmit+0x911/0x1ef0 net/ipv6/ip6_tunnel.c:1390
 __netdev_start_xmit include/linux/netdevice.h:4066 [inline]
 netdev_start_xmit include/linux/netdevice.h:4075 [inline]
 xmit_one net/core/dev.c:3026 [inline]
 dev_hard_start_xmit+0x5f1/0xc70 net/core/dev.c:3042
 __dev_queue_xmit+0x27ee/0x3520 net/core/dev.c:3557
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1390
 neigh_output include/net/neighbour.h:482 [inline]
 ip6_finish_output2+0x1d01/0x2130 net/ipv6/ip6_output.c:120
 ip6_finish_output+0xae9/0xba0 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]
 ip6_local_out+0x15e/0x1d0 net/ipv6/output_core.c:176
 ip6_send_skb net/ipv6/ip6_output.c:1682 [inline]
 ip6_push_pending_frames+0x218/0x4d0 net/ipv6/ip6_output.c:1702
 rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
 rawv6_sendmsg+0x4235/0x4fb0 net/ipv6/raw.c:935
 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+0x7fb/0x9f0 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
==================================================================

Crashes (290):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kmsan-gce	2018/05/01 09:11	https://github.com/google/kmsan.git master	d2d741e5	d5b114b4	.config	log	report	syz	C
ci-upstream-kmsan-gce	2018/10/29 05:51	https://github.com/google/kmsan.git master	4bb25354	9ca2afa1	.config	log	report
ci-upstream-kmsan-gce	2018/10/29 02:56	https://github.com/google/kmsan.git master	4bb25354	9ca2afa1	.config	log	report
ci-upstream-kmsan-gce	2018/10/28 20:37	https://github.com/google/kmsan.git master	4bb25354	6f9b225a	.config	log	report
ci-upstream-kmsan-gce	2018/10/27 15:17	https://github.com/google/kmsan.git master	4bb25354	8efba39a	.config	log	report
ci-upstream-kmsan-gce	2018/10/26 22:46	https://github.com/google/kmsan.git master	4bb25354	a8292de9	.config	log	report
ci-upstream-kmsan-gce	2018/10/26 19:17	https://github.com/google/kmsan.git master	4bb25354	a8292de9	.config	log	report
ci-upstream-kmsan-gce	2018/10/26 15:58	https://github.com/google/kmsan.git master	4bb25354	a8292de9	.config	log	report
ci-upstream-kmsan-gce	2018/10/26 10:18	https://github.com/google/kmsan.git master	4bb25354	a8292de9	.config	log	report
ci-upstream-kmsan-gce	2018/10/26 01:46	https://github.com/google/kmsan.git master	4bb25354	a8292de9	.config	log	report
ci-upstream-kmsan-gce	2018/10/24 01:25	https://github.com/google/kmsan.git master	4bb25354	a8292de9	.config	log	report
ci-upstream-kmsan-gce	2018/10/23 05:17	https://github.com/google/kmsan.git master	4bb25354	ecb386fe	.config	log	report
ci-upstream-kmsan-gce	2018/10/22 19:48	https://github.com/google/kmsan.git master	4bb25354	ecb386fe	.config	log	report
ci-upstream-kmsan-gce	2018/10/21 19:46	https://github.com/google/kmsan.git master	4bb25354	ecb386fe	.config	log	report
ci-upstream-kmsan-gce	2018/10/20 21:17	https://github.com/google/kmsan.git master	4bb25354	ecb386fe	.config	log	report
ci-upstream-kmsan-gce	2018/10/20 06:00	https://github.com/google/kmsan.git master	4bb25354	ecb386fe	.config	log	report
ci-upstream-kmsan-gce	2018/10/18 14:17	https://github.com/google/kmsan.git master	22ec98c3	d257b2d2	.config	log	report
ci-upstream-kmsan-gce	2018/10/18 01:52	https://github.com/google/kmsan.git master	22ec98c3	b2695b95	.config	log	report
ci-upstream-kmsan-gce	2018/10/17 14:29	https://github.com/google/kmsan.git master	22ec98c3	1ba7fd7e	.config	log	report
ci-upstream-kmsan-gce	2018/10/17 13:07	https://github.com/google/kmsan.git master	22ec98c3	1ba7fd7e	.config	log	report
ci-upstream-kmsan-gce	2018/10/16 20:53	https://github.com/google/kmsan.git master	22ec98c3	1ba7fd7e	.config	log	report
ci-upstream-kmsan-gce	2018/10/16 05:17	https://github.com/google/kmsan.git master	22ec98c3	8cd30605	.config	log	report
ci-upstream-kmsan-gce	2018/10/15 16:39	https://github.com/google/kmsan.git master	22ec98c3	caf12900	.config	log	report
ci-upstream-kmsan-gce	2018/10/15 12:24	https://github.com/google/kmsan.git master	22ec98c3	caf12900	.config	log	report
ci-upstream-kmsan-gce	2018/10/15 01:40	https://github.com/google/kmsan.git master	22ec98c3	caf12900	.config	log	report
ci-upstream-kmsan-gce	2018/10/10 01:30	https://github.com/google/kmsan.git master	c2d21df4	8b311eaf	.config	log	report
ci-upstream-kmsan-gce	2018/10/07 22:23	https://github.com/google/kmsan.git master	b2efdb2e	8b311eaf	.config	log	report
ci-upstream-kmsan-gce	2018/10/07 09:19	https://github.com/google/kmsan.git master	b2efdb2e	8b311eaf	.config	log	report
ci-upstream-kmsan-gce	2018/10/04 08:29	https://github.com/google/kmsan.git master	b2efdb2e	8b311eaf	.config	log	report
ci-upstream-kmsan-gce	2018/10/02 22:30	https://github.com/google/kmsan.git master	b2efdb2e	a316a2af	.config	log	report
ci-upstream-kmsan-gce	2018/10/02 10:19	https://github.com/google/kmsan.git master	2b752aff	e06f7713	.config	log	report
ci-upstream-kmsan-gce	2018/10/02 04:29	https://github.com/google/kmsan.git master	2b752aff	e06f7713	.config	log	report
ci-upstream-kmsan-gce	2018/10/01 18:01	https://github.com/google/kmsan.git master	2b752aff	48a50c6b	.config	log	report
ci-upstream-kmsan-gce	2018/10/01 11:14	https://github.com/google/kmsan.git master	2b752aff	48a50c6b	.config	log	report
ci-upstream-kmsan-gce	2018/10/01 01:24	https://github.com/google/kmsan.git master	2b752aff	41e4b329	.config	log	report
ci-upstream-kmsan-gce	2018/09/30 22:18	https://github.com/google/kmsan.git master	2b752aff	41e4b329	.config	log	report
ci-upstream-kmsan-gce	2018/09/28 22:04	https://github.com/google/kmsan.git master	23005322	137d7c66	.config	log	report
ci-upstream-kmsan-gce	2018/09/28 15:35	https://github.com/google/kmsan.git master	23005322	137d7c66	.config	log	report
ci-upstream-kmsan-gce	2018/09/27 21:24	https://github.com/google/kmsan.git master	a5bff9bd	0c2fa87b	.config	log	report
ci-upstream-kmsan-gce	2018/09/26 15:47	https://github.com/google/kmsan.git master	eb2e6759	455b6354	.config	log	report
ci-upstream-kmsan-gce	2018/09/26 13:39	https://github.com/google/kmsan.git master	eb2e6759	455b6354	.config	log	report
ci-upstream-kmsan-gce	2018/09/26 02:15	https://github.com/google/kmsan.git master	eb2e6759	b7e11289	.config	log	report
ci-upstream-kmsan-gce	2018/09/25 14:42	https://github.com/google/kmsan.git master	f94b97e3	0e7547d7	.config	log	report
ci-upstream-kmsan-gce	2018/09/23 17:48	https://github.com/google/kmsan.git master	7ace4303	37079712	.config	log	report
ci-upstream-kmsan-gce	2018/09/23 05:29	https://github.com/google/kmsan.git master	7ace4303	37079712	.config	log	report
ci-upstream-kmsan-gce	2018/09/23 00:35	https://github.com/google/kmsan.git master	7ace4303	37079712	.config	log	report
ci-upstream-kmsan-gce	2018/09/22 20:45	https://github.com/google/kmsan.git master	7ace4303	37079712	.config	log	report
ci-upstream-kmsan-gce	2018/09/22 18:59	https://github.com/google/kmsan.git master	7ace4303	37079712	.config	log	report
ci-upstream-kmsan-gce	2018/09/22 10:42	https://github.com/google/kmsan.git master	7ace4303	37079712	.config	log	report
ci-upstream-kmsan-gce	2018/04/06 23:53	https://github.com/google/kmsan.git master	e2ab7e8a	d613535f	.config	log	report