KASAN: use-after-free Write in skb_release

KASAN: use-after-free Write in skb_release_data (2)
Status: upstream: reported C repro on 2018/10/15 06:30
Reported-by: syzbot+580be3953ed99133804f@syzkaller.appspotmail.com
First crash: 923d, last: 111d

Cause bisection: introduced by (bisect log) :
commit 472c2e07eef045145bc1493cc94a01c87140780a
Author: Eric Dumazet <edumazet@google.com>
Date: Fri Mar 22 15:56:39 2019 +0000

tcp: add one skb cache for tx

Crash: KASAN: use-after-free Write in skb_release_data (log)
Repro: C syz .config

Fix bisection: fixed by (bisect log) [no-op commit]:
commit 31867b23d7d1ee3535136c6a410a6cf56f666bfc
Author: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Fri Dec 28 19:00:38 2018 +0000

f2fs: wait on atomic writes to count F2FS_CP_WB_DATA

similar bugs (5):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
upstream	KASAN: use-after-free Write in skb_release_data	C	1903	1062d	1115d	9/22	fixed on 2018/08/07 13:43
android-414	KASAN: use-after-free Write in skb_release_data		3	553d	632d	0/1	auto-closed as invalid on 2020/02/13 13:09
linux-4.19	KASAN: use-after-free Write in skb_release_data		1	374d	374d	0/1	auto-closed as invalid on 2020/08/10 01:37
linux-4.19	KASAN: use-after-free Write in skb_release_data (2)		2	36d	65d	0/1	upstream: reported on 2021/02/15 01:48
android-54	KASAN: use-after-free Write in skb_release_data		2	266d	296d	0/1	auto-closed as invalid on 2020/11/26 21:03

Sample crash report:

==================================================================
BUG: KASAN: use-after-free in atomic_sub_return include/asm-generic/atomic-instrumented.h:159 [inline]
BUG: KASAN: use-after-free in skb_release_data+0x11d/0x7a0 net/core/skbuff.c:566
Write of size 4 at addr ffff8880a95c27a0 by task syz-executor705/7795

CPU: 0 PID: 7795 Comm: syz-executor705 Not tainted 5.0.0+ #108
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 kasan_check_write+0x14/0x20 mm/kasan/common.c:108
 atomic_sub_return include/asm-generic/atomic-instrumented.h:159 [inline]
 skb_release_data+0x11d/0x7a0 net/core/skbuff.c:566
 skb_release_all+0x4d/0x60 net/core/skbuff.c:631
 __kfree_skb net/core/skbuff.c:645 [inline]
 kfree_skb net/core/skbuff.c:663 [inline]
 kfree_skb+0xe8/0x390 net/core/skbuff.c:657
 __skb_queue_purge include/linux/skbuff.h:2711 [inline]
 inet_sock_destruct+0x10b/0x830 net/ipv4/af_inet.c:138
 __sk_destruct+0x55/0x6d0 net/core/sock.c:1699
 sk_destruct+0x7b/0x90 net/core/sock.c:1734
 __sk_free+0xce/0x300 net/core/sock.c:1745
 sk_free+0x42/0x50 net/core/sock.c:1756
 sock_put include/net/sock.h:1720 [inline]
 sk_common_release+0x224/0x330 net/core/sock.c:3171
 rawv6_close+0x68/0x90 net/ipv6/raw.c:1236
 inet_release+0x105/0x1f0 net/ipv4/af_inet.c:432
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:473
 __sock_release+0xd3/0x2b0 net/socket.c:599
 sock_close+0x1b/0x30 net/socket.c:1247
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x90a/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:980
 get_signal+0x399/0x1d50 kernel/signal.c:2575
 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4459a9
Code: Bad RIP value.
RSP: 002b:00007f46bf5d7da8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006dac48 RCX: 00000000004459a9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dac48
RBP: 00000000006dac40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac4c
R13: 0000000000000000 R14: 0000000000000000 R15: 20c49ba5e353f7cf

Allocated by task 7795:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_kmalloc mm/kasan/common.c:497 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511
 __do_kmalloc_node mm/slab.c:3686 [inline]
 __kmalloc_node_track_caller+0x4e/0x70 mm/slab.c:3700
 __kmalloc_reserve.isra.0+0x40/0xf0 net/core/skbuff.c:140
 __alloc_skb+0x10b/0x5e0 net/core/skbuff.c:208
 alloc_skb_fclone include/linux/skbuff.h:1107 [inline]
 sk_stream_alloc_skb+0x113/0xd10 net/ipv4/tcp.c:889
 tcp_connect+0xfd8/0x4280 net/ipv4/tcp_output.c:3521
 tcp_v6_connect+0x150b/0x20a0 net/ipv6/tcp_ipv6.c:330
 __inet_stream_connect+0x83f/0xea0 net/ipv4/af_inet.c:659
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1158 [inline]
 tcp_sendmsg_locked+0x2314/0x34d0 net/ipv4/tcp.c:1200
 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1434
 inet_sendmsg+0x147/0x5e0 net/ipv4/af_inet.c:802
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:661
 __sys_sendto+0x262/0x380 net/socket.c:1932
 __do_sys_sendto net/socket.c:1944 [inline]
 __se_sys_sendto net/socket.c:1940 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1940
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7795:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3821
 skb_free_head+0x93/0xb0 net/core/skbuff.c:557
 skb_release_data+0x576/0x7a0 net/core/skbuff.c:577
 skb_release_all+0x4d/0x60 net/core/skbuff.c:631
 __kfree_skb net/core/skbuff.c:645 [inline]
 kfree_skb net/core/skbuff.c:663 [inline]
 kfree_skb+0xe8/0x390 net/core/skbuff.c:657
 __skb_queue_purge include/linux/skbuff.h:2711 [inline]
 inet_sock_destruct+0x10b/0x830 net/ipv4/af_inet.c:138
 __sk_destruct+0x55/0x6d0 net/core/sock.c:1699
 sk_destruct+0x7b/0x90 net/core/sock.c:1734
 __sk_free+0xce/0x300 net/core/sock.c:1745
 sk_free+0x42/0x50 net/core/sock.c:1756
 sock_put include/net/sock.h:1720 [inline]
 sk_common_release+0x224/0x330 net/core/sock.c:3171
 rawv6_close+0x68/0x90 net/ipv6/raw.c:1236
 inet_release+0x105/0x1f0 net/ipv4/af_inet.c:432
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:473
 __sock_release+0xd3/0x2b0 net/socket.c:599
 sock_close+0x1b/0x30 net/socket.c:1247
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x90a/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:980
 get_signal+0x399/0x1d50 kernel/signal.c:2575
 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a95c24c0
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 736 bytes inside of
 1024-byte region [ffff8880a95c24c0, ffff8880a95c28c0)
The buggy address belongs to the page:
page:ffffea0002a57080 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea00024cc108 ffffea0002a48a08 ffff88812c3f0ac0
raw: 0000000000000000 ffff8880a95c2040 0000000100000007 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a95c2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a95c2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880a95c2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8880a95c2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a95c2880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (874):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info
ci-upstream-net-kasan-gce	2019/03/26 05:48	net-next	68cc2999	55684ce1	.config	log	report	syz	C
ci-upstream-net-kasan-gce	2019/03/25 03:30	net-next	68cc2999	2c86e0a5	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2019/03/26 06:24	linux-next	9e864317	55684ce1	.config	log	report	syz	C
ci-upstream-kasan-gce-selinux-root	2020/12/31 00:18	upstream	f6e1ea19	ecb8c012	.config	log	report			info
ci-upstream-kasan-gce-root	2018/11/20 02:07	upstream	f2ce1065	adf636a8	.config	log	report
ci-upstream-bpf-kasan-gce	2020/06/29 04:00	bpf	7a64135f	a2cdad9d	.config	log	report
ci-upstream-bpf-kasan-gce	2020/06/25 12:56	bpf	4e15507f	54566aff	.config	log	report
ci-upstream-bpf-kasan-gce	2020/06/24 18:00	bpf	4e15507f	54566aff	.config	log	report
ci-upstream-bpf-kasan-gce	2020/06/17 23:25	bpf	29fcb05b	b9f3810b	.config	log	report
ci-upstream-bpf-kasan-gce	2020/06/12 10:58	bpf	2c4779ef	58802067	.config	log	report
ci-upstream-bpf-kasan-gce	2020/05/19 05:14	bpf	f85c1598	684d3606	.config	log	report
ci-upstream-net-this-kasan-gce	2018/12/08 10:01	net	1b4e5ad5	65ed2472	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/07/11 16:23	bpf-next	eef8a42d	18d18b59	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/07/09 18:47	bpf-next	5cfd607b	bc238812	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/07/09 12:25	bpf-next	5cfd607b	bc238812	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/07/08 08:16	bpf-next	cb8e59cc	51095195	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/07/02 12:53	bpf-next	cb8e59cc	bed10395	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/07/02 08:32	bpf-next	cb8e59cc	bed10395	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/07/01 22:28	bpf-next	cb8e59cc	39acb39d	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/19 16:21	bpf-next	cb8e59cc	bc258b50	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/18 05:03	bpf-next	cb8e59cc	b9f3810b	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/14 04:16	bpf-next	cb8e59cc	dbce178a	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/09 12:28	bpf-next	cb8e59cc	0d60b78a	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/07 06:32	bpf-next	cb8e59cc	e6b89e4e	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/07 03:21	bpf-next	cb8e59cc	e6b89e4e	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/06 16:05	bpf-next	cb8e59cc	e6b89e4e	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/06 14:17	bpf-next	cb8e59cc	e6b89e4e	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/06 00:07	bpf-next	cb8e59cc	f243c88f	.config	log	report
ci-upstream-bpf-next-kasan-gce	2020/06/03 09:04	bpf-next	e8224bfe	f3ba1b5b	.config	log	report
ci-upstream-net-kasan-gce	2019/03/28 02:02	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/28 00:58	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/28 00:49	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 23:48	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 22:48	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 20:15	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 18:26	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 17:23	net-next	5133a4a8	4e668495	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 13:01	net-next	be67101f	55684ce1	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 10:37	net-next	be67101f	55684ce1	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 10:06	net-next	be67101f	55684ce1	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 09:06	net-next	be67101f	55684ce1	.config	log	report
ci-upstream-net-kasan-gce	2019/03/27 08:00	net-next	be67101f	55684ce1	.config	log	report
ci-upstream-net-kasan-gce	2018/10/11 05:22	net-next	e40a826a	5f818b4b	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/28 03:04	linux-next	a392ee45	f94f56fe	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 21:47	linux-next	a392ee45	4e668495	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 21:17	linux-next	a392ee45	4e668495	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 19:03	linux-next	a392ee45	4e668495	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 16:16	linux-next	a392ee45	4e668495	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 15:09	linux-next	a392ee45	4e668495	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 15:06	linux-next	a392ee45	4e668495	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 14:02	linux-next	a392ee45	4e668495	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 11:38	linux-next	a392ee45	55684ce1	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/03/27 06:35	linux-next	a392ee45	55684ce1	.config	log	report