KASAN: use-after-free Read in ext4_xattr_set

KASAN: use-after-free Read in ext4_xattr_set_entry (4)
Status: upstream: reported C repro on 2021/01/30 11:05
Reported-by: syzbot+4cb1e27475bf90a9b926@syzkaller.appspotmail.com
First crash: 363d, last: 4d11h

Cause bisection: failed (bisect log)

similar bugs (13):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.14	KASAN: use-after-free Read in ext4_xattr_set_entry (3)	C			1	28d	453d	0/1	upstream: reported C repro on 2020/10/28 15:08
android-414	KASAN: use-after-free Read in ext4_xattr_set_entry (2)				6	816d	872d	0/1	auto-closed as invalid on 2020/02/28 13:35
linux-4.14	KASAN: use-after-free Read in ext4_xattr_set_entry (2)				1	673d	673d	0/1	auto-closed as invalid on 2020/07/21 03:20
linux-4.19	KASAN: use-after-free Read in ext4_xattr_set_entry (2)	C		done	7	134d	592d	1/1	fixed on 2021/10/13 07:23
upstream	KASAN: use-after-free Read in ext4_xattr_set_entry				1	1277d	1277d	0/22	closed as invalid on 2018/07/29 11:55
android-414	KASAN: use-after-free Read in ext4_xattr_set_entry				4	1124d	1017d	0/1	auto-closed as invalid on 2019/06/26 01:15
upstream	KASAN: use-after-free Read in ext4_xattr_set_entry (3)				4	568d	686d	0/22	auto-closed as invalid on 2020/11/02 08:32
linux-4.19	KASAN: use-after-free Read in ext4_xattr_set_entry	syz		done	10	696d	944d	1/1	fixed on 2020/03/30 09:03
upstream	KASAN: use-after-free Read in ext4_xattr_set_entry (2)	C	done		19	770d	1179d	16/22	fixed on 2020/02/14 01:19
android-54	KASAN: use-after-free Read in ext4_xattr_set_entry				6	536d	717d	0/1	auto-closed as invalid on 2020/12/04 21:44
linux-4.14	KASAN: use-after-free Read in ext4_xattr_set_entry	C		done	9	724d	816d	1/1	fixed on 2020/03/01 21:06
android-54	KASAN: out-of-bounds Read in ext4_xattr_set_entry	C			1	309d	309d	0/1	upstream: reported C repro on 2021/03/21 22:06
linux-4.14	KASAN: out-of-bounds Read in ext4_xattr_set_entry	C			2	15d	287d	0/1	upstream: reported C repro on 2021/04/12 14:20

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2021/06/30 07:46	9m	wanjiabing@vivo.com		linux-next	report log

Sample crash report:

==================================================================
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x3151/0x3780 fs/ext4/xattr.c:1586
Read of size 4 at addr ffff888030c00004 by task syz-executor392/11280

CPU: 0 PID: 11280 Comm: syz-executor392 Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:396 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413
 ext4_xattr_set_entry+0x3151/0x3780 fs/ext4/xattr.c:1586
 ext4_xattr_ibody_set+0x78/0x2b0 fs/ext4/xattr.c:2224
 ext4_xattr_set_handle+0x8f4/0x13e0 fs/ext4/xattr.c:2380
 ext4_xattr_set+0x13a/0x340 fs/ext4/xattr.c:2493
 __vfs_setxattr+0x10e/0x170 fs/xattr.c:177
 __vfs_setxattr_noperm+0x11a/0x4c0 fs/xattr.c:208
 __vfs_setxattr_locked+0x1bf/0x250 fs/xattr.c:266
 vfs_setxattr+0x135/0x320 fs/xattr.c:291
 setxattr+0x1ff/0x290 fs/xattr.c:553
 path_setxattr+0x170/0x190 fs/xattr.c:572
 __do_sys_setxattr fs/xattr.c:587 [inline]
 __se_sys_setxattr fs/xattr.c:583 [inline]
 __x64_sys_setxattr+0xc0/0x160 fs/xattr.c:583
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x445589
Code: e8 4c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b cc fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffdf5f9b28 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 0000000000000016 RCX: 0000000000445589
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000020000100
RBP: 0000000001a18c30 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000073d
R13: 00007fffdf5f9ba0 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:00000000f7ed6945 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x1 pfn:0x30c00
flags: 0xfff00000000000()
raw: 00fff00000000000 ffffea0000c56508 ffffea0000c17d88 0000000000000000
raw: 0000000000000001 0000000000000001 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888030bfff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888030bfff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888030c00000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888030c00080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888030c00100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Fix bisection attempts:
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kasan-gce-root	2021/12/11 21:03	upstream	eccea80be257	52e37319	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2021/10/05 04:19	upstream	f6274b06e326	52e37319	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2021/08/23 02:57	upstream	e22ce8eb631b	52e37319	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2021/07/24 02:38	upstream	f0fddcec6b62	52e37319	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2021/06/23 20:37	upstream	7426cedc7dad	52e37319	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2021/05/24 19:44	upstream	1434a3127887	52e37319	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2021/04/24 19:06	upstream	2a1d7946fa53	52e37319	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2021/03/03 18:26	upstream	f69d02e37a85	52e37319	.config	log	report	syz	C

Crashes (18):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kasan-gce-root	2021/01/26 10:55	upstream	f8ad8187c3b5	52e37319	.config	log	report	syz	C		KASAN: use-after-free Read in ext4_xattr_set_entry
ci-upstream-linux-next-kasan-gce-root	2021/03/25 13:43	linux-next	20f1b5f9c07c	607e3baf	.config	log	report	syz	C		KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2022/01/20 17:43	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	b838eb76	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2022/01/19 13:50	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	0620189b	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2022/01/11 04:15	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	ddb0ab8c	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2022/01/08 03:21	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	2ca0d385	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2022/01/04 09:07	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	7f723fbe	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/12/31 22:30	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	e1768e9c	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/12/31 08:45	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	36bd2e48	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/12/26 11:57	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	e4f103c4	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/12/15 21:18	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	572bcb40	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/11/10 22:26	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	75b04091	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/10/26 19:12	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	3ef6ca4f354c	d50eb50a	.config	log	report			info	KASAN: use-after-free Read in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/12/17 03:48	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	44068e19	.config	log	report			info	KASAN: slab-out-of-bounds Write in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/12/15 21:22	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	64a19591a293	572bcb40	.config	log	report			info	KASAN: use-after-free Write in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/10/26 23:32	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	3ef6ca4f354c	d50eb50a	.config	log	report			info	KASAN: slab-out-of-bounds Write in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/09/05 03:58	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	7d2a07b76933	d236a457	.config	log	report			info	KASAN: slab-out-of-bounds Write in ext4_xattr_set_entry
ci-qemu2-riscv64	2021/08/29 02:31	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes	417166ddec02	be2c130d	.config	log	report			info	KASAN: slab-out-of-bounds Write in ext4_xattr_set_entry