KASAN: slab-out-of-bounds Read in _decode

KASAN: slab-out-of-bounds Read in _decode_session6 (2)
Status: upstream: reported C repro on 2018/10/30 15:00
Reported-by: syzbot+240f9766d6be3d69431e@syzkaller.appspotmail.com
First crash: 963d, last: 942d

Cause bisection: introduced by (bisect log) :
commit 64fd1c7040880292710e6592ddc88d0d73cfb6fb
Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date: Mon Jun 12 20:48:41 2017 +0000

ACPI / PM: Run wakeup notify handlers synchronously

Crash: INFO: trying to register non-static key in can_notifier (log)
Repro: C syz .config

Fix bisection: fixed by (bisect log) [no-op commit]:
commit 62c7139f3ed011379fbbef832b4b15e3c10b355f
Author: Hans Wippel <hwippel@linux.ibm.com>
Date: Thu Feb 7 14:56:17 2019 +0000

net/smc: unlock LGR pending lock earlier for SMC-D

similar bugs (4):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
linux-4.14	KASAN: slab-out-of-bounds Read in _decode_session6		1	399d	399d	0/1	auto-closed as invalid on 2020/09/13 07:38
linux-4.19	KASAN: slab-out-of-bounds Read in _decode_session6		10	31d	469d	0/1	upstream: reported on 2020/03/07 06:45
upstream	KASAN: slab-out-of-bounds Read in _decode_session6	C	35	964d	1021d	12/22	fixed on 2018/10/30 01:28
android-414	KASAN: slab-out-of-bounds Read in _decode_session6	C	42	942d	801d	0/1	public: reported C repro on 2019/04/11 00:00

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: KASAN: slab-out-of-bounds in _decode_session6+0x134a/0x1500 net/ipv6/xfrm6_policy.c:161
Read of size 1 at addr ffff8801cc9bc487 by task syz-executor171/5694

CPU: 1 PID: 5694 Comm: syz-executor171 Not tainted 4.19.0+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 _decode_session6+0x134a/0x1500 net/ipv6/xfrm6_policy.c:161
 __xfrm_decode_session+0x71/0x140 net/xfrm/xfrm_policy.c:2299
 xfrm_decode_session include/net/xfrm.h:1232 [inline]
 vti6_tnl_xmit+0x3fc/0x1c10 net/ipv6/ip6_vti.c:542
 __netdev_start_xmit include/linux/netdevice.h:4336 [inline]
 netdev_start_xmit include/linux/netdevice.h:4345 [inline]
 xmit_one net/core/dev.c:3252 [inline]
 dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3268
 __dev_queue_xmit+0x2f71/0x3ad0 net/core/dev.c:3838
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3871
 __bpf_tx_skb net/core/filter.c:2017 [inline]
 __bpf_redirect_common net/core/filter.c:2055 [inline]
 __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2062
 ____bpf_clone_redirect net/core/filter.c:2095 [inline]
 bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2067
 bpf_prog_c39d1ba309a769f7+0x881/0x1000

Allocated by task 5694:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc_node mm/slab.c:3684 [inline]
 __kmalloc_node_track_caller+0x50/0x70 mm/slab.c:3698
 __kmalloc_reserve.isra.40+0x41/0xe0 net/core/skbuff.c:137
 pskb_expand_head+0x230/0x10f0 net/core/skbuff.c:1460
 skb_ensure_writable+0x3dd/0x640 net/core/skbuff.c:5071
 __bpf_try_make_writable net/core/filter.c:1638 [inline]
 bpf_try_make_writable net/core/filter.c:1644 [inline]
 bpf_try_make_head_writable net/core/filter.c:1652 [inline]
 ____bpf_clone_redirect net/core/filter.c:2089 [inline]
 bpf_clone_redirect+0x14a/0x490 net/core/filter.c:2067
 bpf_prog_c39d1ba309a769f7+0x881/0x1000

Freed by task 4310:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3817
 load_elf_binary+0x25b4/0x5620 fs/binfmt_elf.c:1118
 search_binary_handler+0x17d/0x570 fs/exec.c:1653
 exec_binprm fs/exec.c:1695 [inline]
 __do_execve_file.isra.33+0x1661/0x25d0 fs/exec.c:1819
 do_execveat_common fs/exec.c:1866 [inline]
 do_execve fs/exec.c:1883 [inline]
 __do_sys_execve fs/exec.c:1964 [inline]
 __se_sys_execve fs/exec.c:1959 [inline]
 __x64_sys_execve+0x8f/0xc0 fs/exec.c:1959
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801cc9bc280
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 7 bytes to the right of
 512-byte region [ffff8801cc9bc280, ffff8801cc9bc480)
The buggy address belongs to the page:
page:ffffea0007326f00 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0
flags: 0x2fffc0000000200(slab)
raw: 02fffc0000000200 ffffea000734e788 ffffea0007302848 ffff8801da800940
raw: 0000000000000000 ffff8801cc9bc000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cc9bc380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801cc9bc400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801cc9bc480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8801cc9bc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cc9bc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (26):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kasan-gce-smack-root	2018/10/30 21:04	upstream	11743c56	8dbb755a	.config	log	report	syz	C
ci-upstream-kasan-gce-selinux-root	2018/10/30 20:10	upstream	11743c56	8dbb755a	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2018/10/30 15:24	upstream	11743c56	8dbb755a	.config	log	report	syz	C
ci-upstream-net-this-kasan-gce	2018/10/30 15:24	net	da715775	8dbb755a	.config	log	report	syz	C
ci-upstream-bpf-kasan-gce	2018/10/30 14:58	bpf	d8fd9e10	8dbb755a	.config	log	report	syz	C
ci-upstream-bpf-next-kasan-gce	2018/10/30 15:23	bpf-next	44adbac8	8dbb755a	.config	log	report	syz	C
ci-upstream-net-kasan-gce	2018/10/30 15:22	net-next	4b427452	8dbb755a	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2018/10/30 15:23	linux-next	6201f31a	8dbb755a	.config	log	report	syz	C
ci-upstream-kasan-gce-smack-root	2018/11/07 04:05	upstream	8053e5b9	8bd6bd63	.config	log	report
ci-upstream-kasan-gce-smack-root	2018/11/05 00:46	upstream	4710e789	8bd6bd63	.config	log	report
ci-upstream-kasan-gce-smack-root	2018/11/02 20:15	upstream	d81f50bd	8bd6bd63	.config	log	report
ci-upstream-bpf-kasan-gce	2018/11/18 12:52	bpf	569a933b	adf636a8	.config	log	report
ci-upstream-bpf-kasan-gce	2018/11/16 21:35	bpf	da85d8bf	b08ee62a	.config	log	report
ci-upstream-bpf-kasan-gce	2018/11/15 23:56	bpf	da85d8bf	3a41052e	.config	log	report
ci-upstream-bpf-kasan-gce	2018/11/14 22:01	bpf	da85d8bf	5f5f6d14	.config	log	report
ci-upstream-bpf-kasan-gce	2018/10/31 01:04	bpf	27b31e68	4ccf7bb4	.config	log	report
ci-upstream-bpf-kasan-gce	2018/10/30 13:27	bpf	d8fd9e10	8dbb755a	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/20 20:05	bpf-next	740baecd	9aca6b52	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/20 06:58	bpf-next	bbe5d311	9bc2a903	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/19 23:42	bpf-next	592ee43f	adf636a8	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/17 20:58	bpf-next	592ee43f	adf636a8	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/17 17:36	bpf-next	592ee43f	b08ee62a	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/16 20:37	bpf-next	407be8d0	b08ee62a	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/16 07:54	bpf-next	407be8d0	f5e275d1	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/11/10 00:20	bpf-next	c8123ead	f9815aaf	.config	log	report
ci-upstream-bpf-next-kasan-gce	2018/10/30 18:42	bpf-next	44adbac8	8dbb755a	.config	log	report