KASAN: stack-out-of-bounds Read in xfrm_selector

KASAN: stack-out-of-bounds Read in xfrm_selector_match
Status: public: reported C repro on 2019/04/11 08:44
Reported-by: syzbot+c8463c5b3015c191734e@syzkaller.appspotmail.com
First crash: 618d, last: 387d

similar bugs (4):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
android-49	KASAN: stack-out-of-bounds Read in xfrm_selector_match	C	672	377d	844d	0/3	closed as invalid on 2018/11/08 02:37
upstream	KASAN: stack-out-of-bounds Read in xfrm_selector_match		368	674d	681d	4/14	fixed on 2018/02/13 04:59
android-414	KASAN: stack-out-of-bounds Read in xfrm_selector_match		1	25d	25d	0/1	public: reported on 2019/10/22 15:26
android-49	KASAN: stack-out-of-bounds Read in xfrm_selector_match (2)	C	13	23d	218d	0/3	public: reported C repro on 2019/04/13 00:00

Sample crash report:

random: sshd: uninitialized urandom read (32 bytes read, 101 bits of entropy available)
random: sshd: uninitialized urandom read (32 bytes read, 104 bits of entropy available)
random: sshd: uninitialized urandom read (32 bytes read, 111 bits of entropy available)
==================================================================
BUG: KASAN: stack-out-of-bounds in memcmp+0x126/0x160 lib/string.c:742
Read of size 1 at addr ffff8801c87678e0 by task syzkaller311351/3732

CPU: 1 PID: 3732 Comm: syzkaller311351 Not tainted 4.4.125-g38f41ec #63
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 847c5155748e9cda ffff8801c8767418 ffffffff81d067bd
 ffffea000721d9c0 ffff8801c87678e0 0000000000000000 ffff8801c87678e0
 ffff8801c87678c8 ffff8801c8767450 ffffffff814fea83 ffff8801c87678e0
Call Trace:
 [<ffffffff81d067bd>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d067bd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff814fea83>] print_address_description+0x73/0x260 mm/kasan/report.c:252
 [<ffffffff814fef95>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff814fef95>] kasan_report+0x285/0x370 mm/kasan/report.c:408
 [<ffffffff814ff094>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:426
 [<ffffffff81d22bd6>] memcmp+0x126/0x160 lib/string.c:742
 [<ffffffff832ae477>] addr_match include/net/xfrm.h:837 [inline]
 [<ffffffff832ae477>] __xfrm6_selector_match net/xfrm/xfrm_policy.c:81 [inline]
 [<ffffffff832ae477>] xfrm_selector_match+0x1c7/0xe50 net/xfrm/xfrm_policy.c:95
 [<ffffffff832af253>] xfrm_sk_policy_lookup+0x153/0x360 net/xfrm/xfrm_policy.c:1236
 [<ffffffff832b1fee>] xfrm_lookup+0x1be/0xc10 net/xfrm/xfrm_policy.c:2184
 [<ffffffff832b3949>] xfrm_lookup_route+0x39/0x1a0 net/xfrm/xfrm_policy.c:2318
 [<ffffffff833084d4>] ip6_dst_lookup_flow+0x1b4/0x2e0 net/ipv6/ip6_output.c:1070
 [<ffffffff833ae37e>] tcp_v6_connect+0xade/0x1b90 net/ipv6/tcp_ipv6.c:249
 [<ffffffff831d6e26>] __inet_stream_connect+0x2a6/0xc70 net/ipv4/af_inet.c:615
 [<ffffffff83126e11>] tcp_sendmsg_fastopen net/ipv4/tcp.c:1092 [inline]
 [<ffffffff83126e11>] tcp_sendmsg+0xcc1/0x2b10 net/ipv4/tcp.c:1112
 [<ffffffff831dde2c>] inet_sendmsg+0x2bc/0x4c0 net/ipv4/af_inet.c:755
 [<ffffffff82df168a>] sock_sendmsg_nosec net/socket.c:625 [inline]
 [<ffffffff82df168a>] sock_sendmsg+0xca/0x110 net/socket.c:635
 [<ffffffff82df25d8>] SYSC_sendto+0x2c8/0x340 net/socket.c:1665
 [<ffffffff82df4ad0>] SyS_sendto+0x40/0x50 net/socket.c:1633
 [<ffffffff83779965>] entry_SYSCALL_64_fastpath+0x22/0x9e

The buggy address belongs to the page:
page:ffffea000721d9c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c8767780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c8767800: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2
>ffff8801c8767880: f2 f2 00 00 00 00 00 00 00 00 00 00 f2 f2 00 00
                                                       ^
 ffff8801c8767900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c8767980: 00 00 00 f1 f1 f1 f1 00 00 00 00 00 f2 f2 f2 00
==================================================================

Crashes (36):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-android-44-kasan-gce	2018/04/10 13:37	android-4.4	38f41ec1	8e873e9d	.config	log	report	syz	C
ci-android-44-kasan-gce	2018/07/17 02:33	android-4.4	ed9bdc8a	40cb0c9a	.config	log	report	syz	C
ci-android-44-kasan-gce-386	2018/04/10 13:24	android-4.4	38f41ec1	8e873e9d	.config	log	report	syz
ci-android-44-kasan-gce	2018/03/08 22:32	android-4.4	d63fdf61	acd0caa5	.config	log	report
ci-android-44-kasan-gce	2018/10/25 21:29	android-4.4	c4b00eb7	a8292de9	.config	log	report
ci-android-44-kasan-gce	2018/10/22 08:57	android-4.4	3eb8e735	ecb386fe	.config	log	report
ci-android-44-kasan-gce	2018/10/10 09:45	android-4.4	ea3a6005	8b311eaf	.config	log	report
ci-android-44-kasan-gce	2018/10/06 15:02	android-4.4	ea3a6005	8b311eaf	.config	log	report
ci-android-44-kasan-gce	2018/08/26 14:03	android-4.4	e5c5f1fa	758cd203	.config	log	report
ci-android-44-kasan-gce	2018/08/18 12:18	android-4.4	f76bdbdd	db1858f6	.config	log	report
ci-android-44-kasan-gce	2018/08/11 05:20	android-4.4	a5fc6659	7a88b141	.config	log	report
ci-android-44-kasan-gce	2018/08/03 08:18	android-4.4	2241aa98	5b7e23bb	.config	log	report
ci-android-44-kasan-gce	2018/07/31 06:42	android-4.4	8ddb600e	1a381291	.config	log	report
ci-android-44-kasan-gce	2018/07/23 22:09	android-4.4	1b37d68f	912c93d7	.config	log	report
ci-android-44-kasan-gce	2018/07/15 13:40	android-4.4	ed9bdc8a	92a49505	.config	log	report
ci-android-44-kasan-gce	2018/06/30 19:59	android-4.4	cf21a9ac	dba0b50e	.config	log	report
ci-android-44-kasan-gce	2018/06/29 00:28	android-4.4	cf21a9ac	dba0b50e	.config	log	report
ci-android-44-kasan-gce	2018/06/28 15:21	android-4.4	cf21a9ac	dba0b50e	.config	log	report
ci-android-44-kasan-gce	2018/06/24 07:24	android-4.4	226f96b0	2064fc5c	.config	log	report
ci-android-44-kasan-gce	2018/06/24 01:05	android-4.4	226f96b0	2064fc5c	.config	log	report
ci-android-44-kasan-gce	2018/06/19 18:33	android-4.4	226f96b0	732e4256	.config	log	report
ci-android-44-kasan-gce	2018/06/19 16:42	android-4.4	226f96b0	732e4256	.config	log	report
ci-android-44-kasan-gce	2018/06/08 09:11	android-4.4	fb7e3196	f7b27b7a	.config	log	report
ci-android-44-kasan-gce	2018/06/06 11:30	android-4.4	7e3a6fc4	41f9540d	.config	log	report
ci-android-44-kasan-gce	2018/05/29 15:49	android-4.4	3f51ea2d	e276de77	.config	log	report
ci-android-44-kasan-gce	2018/05/18 19:43	android-4.4	46155cc7	849705db	.config	log	report
ci-android-44-kasan-gce	2018/05/17 09:36	android-4.4	46155cc7	a367c1d7	.config	log	report
ci-android-44-kasan-gce	2018/05/17 08:08	android-4.4	46155cc7	a367c1d7	.config	log	report
ci-android-44-kasan-gce	2018/05/13 11:59	android-4.4	aa3863d2	c05b619d	.config	log	report
ci-android-44-kasan-gce	2018/05/10 21:36	android-4.4	3702e76f	12c7428a	.config	log	report
ci-android-44-kasan-gce	2018/05/10 03:15	android-4.4	033c952f	12c7428a	.config	log	report
ci-android-44-kasan-gce	2018/05/08 00:43	android-4.4	fcce5711	9e0846e8	.config	log	report
ci-android-44-kasan-gce	2018/05/04 07:39	android-4.4	1fe7e920	9ce14f4b	.config	log	report
ci-android-44-kasan-gce-386	2018/04/19 07:23	android-4.4	38f41ec1	829f0234	.config	log	report
ci-android-44-kasan-gce-386	2018/04/18 12:20	android-4.4	38f41ec1	52643b44	.config	log	report
ci-android-44-kasan-gce-386	2018/04/10 12:36	android-4.4	38f41ec1	8e873e9d	.config	log	report