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

Status: auto-closed as invalid on 2020/02/28 13:35
Reported-by: syzbot+760383f25b4a8f05bb3d@syzkaller.appspotmail.com
First crash: 2237d, last: 2182d
▶ ▼ Similar bugs (15)
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 1333d 1819d 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 5 7d12h 110d 0/2 upstream: reported C repro on 2025/07/03 01:48
linux-4.14 KASAN: use-after-free Read in ext4_xattr_set_entry (2) 19 1 2038d 2038d 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) 19 C done 7 1499d 1958d 1/1 fixed on 2021/10/13 07:23
upstream KASAN: use-after-free Read in ext4_xattr_set_entry ext4 19 1 2642d 2642d 0/29 closed as invalid on 2018/07/29 11:55
android-414 KASAN: use-after-free Read in ext4_xattr_set_entry 19 4 2489d 2382d 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 1183d 1242d 0/29 auto-obsoleted due to no activity on 2022/11/22 17:19
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (3) ext4 19 4 1934d 2052d 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 2061d 2309d 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 1338d 1725d 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 2136d 2544d 15/29 fixed on 2020/02/14 01:19
android-54 KASAN: use-after-free Read in ext4_xattr_set_entry 19 6 1901d 2082d 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 19 C inconclusive 451 6h47m 886d 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 38 5h27m 762d 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 2089d 2182d 1/1 fixed on 2020/03/01 21:06

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x2e28/0x2f00 fs/ext4/xattr.c:1602
Read of size 4 at addr ffff88819a8b41a6 by task syz-executor.2/10215

CPU: 1 PID: 10215 Comm: syz-executor.2 Not tainted 4.14.151+ #0
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xca/0x134 lib/dump_stack.c:53
 print_address_description+0x60/0x226 mm/kasan/report.c:187
 __kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316
 ext4_xattr_set_entry+0x2e28/0x2f00 fs/ext4/xattr.c:1602
 ext4_xattr_ibody_set+0x73/0x280 fs/ext4/xattr.c:2238
 ext4_xattr_set_handle+0x508/0xdd0 fs/ext4/xattr.c:2394
 ext4_initxattrs+0xb5/0x110 fs/ext4/xattr_security.c:43
 security_inode_init_security security/security.c:493 [inline]
 security_inode_init_security+0x246/0x330 security/security.c:466
 __ext4_new_inode+0x336f/0x4850 fs/ext4/ialloc.c:1166
 ext4_mkdir+0x2f7/0xb50 fs/ext4/namei.c:2776
 vfs_mkdir2+0x3c7/0x640 fs/namei.c:3967
 SYSC_mkdirat fs/namei.c:3996 [inline]
 SyS_mkdirat+0x125/0x220 fs/namei.c:3980
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459367
RSP: 002b:00007ffd83ccf7d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 000000000004835d RCX: 0000000000459367
RDX: 00007ffd83ccf824 RSI: 00000000000001ff RDI: 00007ffd83ccf820
RBP: 0000000000000141 R08: 0000000000000000 R09: 0000000000000004
R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000015
R13: 00007ffd83ccf810 R14: 0000000000048198 R15: 00007ffd83ccf820

The buggy address belongs to the page:
page:ffffea00066a2d00 count:0 mapcount:-127 mapping:          (null) index:0x1
flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000001 00000000ffffff80
raw: ffffea0006c6b520 ffffea00070a9da0 0000000000000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88819a8b4080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88819a8b4100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88819a8b4180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88819a8b4200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88819a8b4280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/31 13:34 android-4.14 2bb70f40b08b a41ca8fa .config console log report ci-android-414-kasan-gce-root
2019/10/29 09:46 android-4.14 c9a4502888e7 5ea87a66 .config console log report ci-android-414-kasan-gce-root
2019/10/28 18:16 android-4.14 0b383e2946f5 439d7b14 .config console log report ci-android-414-kasan-gce-root
2019/10/19 20:05 android-4.14 234de92896af 8c88c9c1 .config console log report ci-android-414-kasan-gce-root
2019/09/26 00:20 android-4.14 d649ef04c3ed a3355dba .config console log report ci-android-414-kasan-gce-root
2019/09/05 20:30 android-4.14 38733badc0e6 040fda58 .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.