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KASAN: use-after-free Read in ext4_xattr_set_entry (2)

Status: auto-closed as invalid on 2020/07/21 03:20
Reported-by: syzbot+001dd339ee946331c255@syzkaller.appspotmail.com
First crash: 2142d, last: 2142d
▶ ▼ Similar bugs (17)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 KASAN: use-after-free Read in ext4_xattr_set_entry (3) 19 C error 1 1438d 1923d 0/1 upstream: reported C repro on 2020/10/28 15:08
android-5-15 KASAN: out-of-bounds Read in ext4_xattr_set_entry (2) origin:lts 19 C 46 3d08h 214d 0/2 upstream: reported C repro on 2025/07/03 01:48
android-414 KASAN: use-after-free Read in ext4_xattr_set_entry (2) 19 6 2286d 2342d 0/1 auto-closed as invalid on 2020/02/28 13:35
linux-4.19 KASAN: use-after-free Read in ext4_xattr_set_entry (2) 19 C done 7 1604d 2062d 1/1 fixed on 2021/10/13 07:23
upstream KASAN: use-after-free Read in ext4_xattr_set_entry ext4 19 1 2747d 2747d 0/29 closed as invalid on 2018/07/29 11:55
upstream KASAN: out-of-bounds Read in ext4_xattr_set_entry ext4 24 C error 6306 1h56m 498d 0/29 upstream: reported C repro on 2024/09/22 00:16
android-414 KASAN: use-after-free Read in ext4_xattr_set_entry 19 4 2593d 2486d 0/1 auto-closed as invalid on 2019/06/26 01:15
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (5) ext4 19 2 1288d 1346d 0/29 auto-obsoleted due to no activity on 2022/11/22 17:19
linux-5.15 KASAN: out-of-bounds Read in ext4_xattr_set_entry origin:upstream 19 C error 53 16h40m 324d 0/3 upstream: reported C repro on 2025/03/15 11:50
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (3) ext4 19 4 2038d 2156d 0/29 auto-closed as invalid on 2020/11/02 08:32
linux-4.19 KASAN: use-after-free Read in ext4_xattr_set_entry 19 syz done 10 2165d 2414d 1/1 fixed on 2020/03/30 09:03
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (4) ext4 24 C error done 21 1442d 1829d 20/29 fixed on 2022/03/28 10:17
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (2) ext4 19 C done 19 2240d 2649d 15/29 fixed on 2020/02/14 01:19
android-54 KASAN: use-after-free Read in ext4_xattr_set_entry 19 6 2006d 2187d 0/2 auto-closed as invalid on 2020/12/04 21:44
linux-6.1 KASAN: out-of-bounds Read in ext4_xattr_set_entry missing-backport origin:lts-only 23 C inconclusive 776 7h08m 990d 0/3 upstream: reported C repro on 2023/05/19 08:42
android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry 19 C inconclusive 57 7d17h 866d 0/2 upstream: reported C repro on 2023/09/20 02:40
linux-4.14 KASAN: use-after-free Read in ext4_xattr_set_entry 19 C done 9 2194d 2286d 1/1 fixed on 2020/03/01 21:06

Sample crash report:
EXT4-fs error (device sda1): ext4_xattr_set_entry:1605: inode #17230: comm syz-fuzzer: corrupted xattr entries
EXT4-fs error (device sda1): ext4_xattr_set_entry:1605: inode #17230: comm syz-fuzzer: corrupted xattr entries
EXT4-fs error (device sda1): ext4_xattr_ibody_find:2191: inode #17231: comm restorecond: corrupted in-inode xattr
==================================================================
EXT4-fs error (device sda1): ext4_xattr_ibody_get:590: inode #17231: comm syz-fuzzer: corrupted in-inode xattr
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x2ed2/0x2fc0 fs/ext4/xattr.c:1602
Read of size 4 at addr ffff888079481002 by task syz-fuzzer/7361

CPU: 1 PID: 7361 Comm: syz-fuzzer Not tainted 4.14.174-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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
 ext4_xattr_set_entry+0x2ed2/0x2fc0 fs/ext4/xattr.c:1602
 ext4_xattr_ibody_set+0x73/0x280 fs/ext4/xattr.c:2238
 ext4_xattr_set_handle+0x4f5/0xda0 fs/ext4/xattr.c:2394
 ext4_initxattrs+0xb5/0x110 fs/ext4/xattr_security.c:43
 security_inode_init_security security/security.c:492 [inline]
 security_inode_init_security+0x236/0x320 security/security.c:465
 __ext4_new_inode+0x353a/0x4e90 fs/ext4/ialloc.c:1171
 ext4_mkdir+0x2e4/0xb60 fs/ext4/namei.c:2665
 vfs_mkdir+0x3af/0x620 fs/namei.c:3849
 SYSC_mkdirat fs/namei.c:3872 [inline]
 SyS_mkdirat+0x1bc/0x210 fs/namei.c:3856
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x47c530
RSP: 002b:000000c43f397990 EFLAGS: 00000206 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530
RDX: 00000000000001c0 RSI: 000000c4236b81e0 RDI: ffffffffffffff9c
RBP: 000000c43f3979f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffffff
R13: 0000000000000010 R14: 000000000000000f R15: 0000000000000100

The buggy address belongs to the page:
page:ffffea0001e52040 count:0 mapcount:-127 mapping:          (null) index:0x1
flags: 0xfffe0000000000()
raw: 00fffe0000000000 0000000000000000 0000000000000001 00000000ffffff80
raw: ffffea00017536e0 ffffea00018711a0 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888079480f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888079480f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888079481000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888079481080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888079481100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/03/23 03:19 linux-4.14.y 01364dad1d45 78267cec .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.