KASAN: use-after-free Read in xfrm6_tunnel

KASAN: use-after-free Read in xfrm6_tunnel_destroy
Status: upstream: reported C repro on 2019/04/12 04:12
Reported-by: syzbot+74900e5257bb7d5c7cc3@syzkaller.appspotmail.com
First crash: 895d, last: 18d

similar bugs (4):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
android-44	KASAN: use-after-free Read in xfrm6_tunnel_destroy (2)		1	744d	744d	0/2	auto-closed as invalid on 2020/01/08 12:52
android-414	KASAN: use-after-free Read in xfrm6_tunnel_destroy	C	34461	660d	897d	0/1	public: reported C repro on 2019/04/10 15:44
android-44	KASAN: use-after-free Read in xfrm6_tunnel_destroy		4	994d	893d	0/2	auto-closed as invalid on 2019/07/02 12:36
android-49	KASAN: use-after-free Read in xfrm6_tunnel_destroy	C	36181	659d	896d	0/3	public: reported C repro on 2019/04/12 00:00

Sample crash report:

IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: use-after-free in xfrm6_tunnel_free_spi net/ipv6/xfrm6_tunnel.c:208 [inline]
BUG: KASAN: use-after-free in xfrm6_tunnel_destroy+0x519/0x5c0 net/ipv6/xfrm6_tunnel.c:303
Read of size 8 at addr ffff88809e0721b8 by task kworker/1:1/23

CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 4.14.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events xfrm_state_gc_task
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1e2 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2ae mm/kasan/report.c:393
 xfrm6_tunnel_free_spi net/ipv6/xfrm6_tunnel.c:208 [inline]
 xfrm6_tunnel_destroy+0x519/0x5c0 net/ipv6/xfrm6_tunnel.c:303
 xfrm_state_gc_destroy net/xfrm/xfrm_state.c:449 [inline]
 xfrm_state_gc_task+0x4ad/0x7d0 net/xfrm/xfrm_state.c:472
 process_one_work+0x813/0x1540 kernel/workqueue.c:2114
 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 7443:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15b/0x7c0 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 ops_init+0xe7/0x3c0 net/core/net_namespace.c:108
 setup_net+0x22f/0x500 net/core/net_namespace.c:295
 copy_net_ns+0x19b/0x440 net/core/net_namespace.c:419
 create_new_namespaces+0x375/0x730 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xa5/0x1e0 kernel/nsproxy.c:206
 SYSC_unshare kernel/fork.c:2391 [inline]
 SyS_unshare+0x2ea/0x740 kernel/fork.c:2341
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 878:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcb/0x260 mm/slab.c:3815
 ops_free net/core/net_namespace.c:132 [inline]
 ops_free_list.part.0+0x1f9/0x330 net/core/net_namespace.c:154
 ops_free_list net/core/net_namespace.c:152 [inline]
 cleanup_net+0x453/0x820 net/core/net_namespace.c:488
 process_one_work+0x813/0x1540 kernel/workqueue.c:2114
 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

The buggy address belongs to the object at ffff88809e0719c0
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 2040 bytes inside of
 8192-byte region [ffff88809e0719c0, ffff88809e0739c0)
The buggy address belongs to the page:
page:ffffea0002781c00 count:1 mapcount:0 mapping:ffff88809e0719c0 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff88809e0719c0 0000000000000000 0000000100000001
raw: ffffea00026e9b20 ffffea00026d5b20 ffff88812fe55080 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809e072080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809e072100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809e072180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88809e072200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809e072280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Fix bisection attempts:
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci2-linux-4-14	2021/09/05 11:19	linux-4.14.y	f96eb53cbd76	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2021/08/06 10:44	linux-4.14.y	94cb1fed447a	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2021/07/07 10:14	linux-4.14.y	313e82bbefb3	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2021/06/07 09:44	linux-4.14.y	a6b2dae3ee3a	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2021/01/27 14:51	linux-4.14.y	2d2791fce891	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2020/12/03 15:40	linux-4.14.y	c196b3a9c83a	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2020/11/03 14:58	linux-4.14.y	2b7915014161	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2020/10/04 13:57	linux-4.14.y	bae31eef2a16	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2020/09/04 10:16	linux-4.14.y	2f166cdcf8a9	749688d2	.config	log	report	syz	C

Crashes (1692):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-linux-4-14	2020/03/17 15:00	linux-4.14.y	12cd844a39ed	749688d2	.config	log	report	syz	C
ci2-linux-4-14	2019/11/22 03:57	linux-4.14.y	f56f3d0e65ad	8098ea0f	.config	log	report	syz	C
ci2-linux-4-14	2019/11/06 20:03	linux-4.14.y	c9fda4f22428	da505f84	.config	log	report	syz	C
ci2-linux-4-14	2019/10/31 04:23	linux-4.14.y	ddef1e8e3f6e	a41ca8fa	.config	log	report	syz	C
ci2-linux-4-14	2019/10/24 00:54	linux-4.14.y	b98aebd29824	b602d64b	.config	log	report	syz	C
ci2-linux-4-14	2019/10/20 03:35	linux-4.14.y	b98aebd29824	8c88c9c1	.config	log	report	syz	C
ci2-linux-4-14	2019/09/22 15:44	linux-4.14.y	f6e27dbb1afa	d96e88f3	.config	log	report	syz	C
ci2-linux-4-14	2019/09/22 10:15	linux-4.14.y	f6e27dbb1afa	d96e88f3	.config	log	report	syz	C
ci2-linux-4-14	2019/07/03 04:05	linux-4.14.y	f4cc0ed9b2c7	55565fa0	.config	log	report	syz	C
ci2-linux-4-14	2019/06/28 20:16	linux-4.14.y	f4cc0ed9b2c7	7509bf36	.config	log	report	syz	C
ci2-linux-4-14	2019/04/30 09:24	linux-4.14.y	fa5941f45d7e	20f16bef	.config	log	report	syz	C
ci2-linux-4-14	2019/04/28 21:35	linux-4.14.y	fa5941f45d7e	b617407b	.config	log	report	syz	C
ci2-linux-4-14	2019/04/16 20:48	linux-4.14.y	1ec8f1f0bffe	505ab413	.config	log	report	syz
ci2-linux-4-14	2021/05/08 09:07	linux-4.14.y	7d7d1c0ab3eb	bc5434be	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/05/04 02:54	linux-4.14.y	7d7d1c0ab3eb	09efdd63	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/05/01 13:47	linux-4.14.y	7d7d1c0ab3eb	77e2b668	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/04/20 07:58	linux-4.14.y	cf256fbcbe34	c0ced557	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/04/10 03:26	linux-4.14.y	0cc244011f40	6a81331a	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/04/08 10:58	linux-4.14.y	0cc244011f40	6a81331a	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/03/21 06:50	linux-4.14.y	cb83ddcd5332	17810eae	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/03/16 16:16	linux-4.14.y	c7150cd2fa8c	fdb2bb2c	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/03/10 09:04	linux-4.14.y	1d177c0872ab	26967e35	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/02/25 15:17	linux-4.14.y	3242aa3a635c	76f7fc95	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2021/02/22 14:13	linux-4.14.y	29c52025152b	c26fb06b	.config	log	report			info	KASAN: use-after-free Read in xfrm6_tunnel_destroy
ci2-linux-4-14	2020/12/28 14:08	linux-4.14.y	3f2ecb86cb90	8259d56c	.config	log	report			info
ci2-linux-4-14	2020/08/05 09:31	linux-4.14.y	ca4f2c56d416	b7129355	.config	log	report
ci2-linux-4-14	2020/08/04 18:39	linux-4.14.y	7f2c5eb458b8	80a06902	.config	log	report
ci2-linux-4-14	2020/07/31 08:21	linux-4.14.y	e5a54aa2d312	8df85ed9	.config	log	report
ci2-linux-4-14	2020/07/29 02:48	linux-4.14.y	69b94dd6dcd1	cb93dc6a	.config	log	report
ci2-linux-4-14	2020/07/24 22:58	linux-4.14.y	69b94dd6dcd1	0a13649c	.config	log	report
ci2-linux-4-14	2020/07/18 23:27	linux-4.14.y	b850307b279c	9c812472	.config	log	report
ci2-linux-4-14	2020/07/13 01:29	linux-4.14.y	b850307b279c	9ebcc5b1	.config	log	report
ci2-linux-4-14	2020/07/07 05:42	linux-4.14.y	b850307b279c	ef278c73	.config	log	report
ci2-linux-4-14	2020/06/27 08:10	linux-4.14.y	b850307b279c	ffec44b5	.config	log	report
ci2-linux-4-14	2020/06/20 15:54	linux-4.14.y	b850307b279c	c655ec77	.config	log	report
ci2-linux-4-14	2020/06/14 11:37	linux-4.14.y	b850307b279c	2a22c77a	.config	log	report
ci2-linux-4-14	2020/06/12 11:22	linux-4.14.y	b850307b279c	819b58b0	.config	log	report
ci2-linux-4-14	2020/06/11 08:20	linux-4.14.y	b850307b279c	3ab7a05a	.config	log	report
ci2-linux-4-14	2020/06/10 07:25	linux-4.14.y	c6db52a88798	860c4de9	.config	log	report
ci2-linux-4-14	2020/06/10 02:13	linux-4.14.y	c6db52a88798	860c4de9	.config	log	report
ci2-linux-4-14	2020/06/10 00:55	linux-4.14.y	c6db52a88798	860c4de9	.config	log	report
ci2-linux-4-14	2020/06/09 12:05	linux-4.14.y	c6db52a88798	0d60b78a	.config	log	report
ci2-linux-4-14	2020/06/08 11:08	linux-4.14.y	c6db52a88798	7604bb03	.config	log	report
ci2-linux-4-14	2020/06/07 02:44	linux-4.14.y	c6db52a88798	e6b89e4e	.config	log	report
ci2-linux-4-14	2020/05/31 21:31	linux-4.14.y	4f68020fef1c	a0331e89	.config	log	report
ci2-linux-4-14	2020/05/26 10:29	linux-4.14.y	a41ba30d9df2	8ca3b7d2	.config	log	report
ci2-linux-4-14	2020/05/25 00:56	linux-4.14.y	a41ba30d9df2	11284182	.config	log	report
ci2-linux-4-14	2020/05/22 03:42	linux-4.14.y	a41ba30d9df2	4afdfa20	.config	log	report
ci2-linux-4-14	2020/04/28 06:55	linux-4.14.y	050272a0423e	0ce7569e	.config	log	report
ci2-linux-4-14	2020/04/27 22:54	linux-4.14.y	050272a0423e	0ce7569e	.config	log	report
ci2-linux-4-14	2020/04/25 16:57	linux-4.14.y	050272a0423e	a113ba38	.config	log	report
ci2-linux-4-14	2020/04/25 04:01	linux-4.14.y	050272a0423e	03d97a1b	.config	log	report
ci2-linux-4-14	2020/04/25 00:51	linux-4.14.y	050272a0423e	03d97a1b	.config	log	report
ci2-linux-4-14	2020/04/24 23:12	linux-4.14.y	050272a0423e	03d97a1b	.config	log	report
ci2-linux-4-14	2020/04/23 10:26	linux-4.14.y	c10b57a567e4	2e44d63e	.config	log	report
ci2-linux-4-14	2020/04/23 07:14	linux-4.14.y	c10b57a567e4	2e44d63e	.config	log	report
ci2-linux-4-14	2020/04/23 02:05	linux-4.14.y	c10b57a567e4	2e44d63e	.config	log	report
ci2-linux-4-14	2019/04/12 03:11	linux-4.14.y	1ec8f1f0bffe	8916f5e1	.config	log	report