In the Linux kernel, the following vulnerability has been resolved:

ext4: avoid OOB when system.data xattr changes underneath the filesystem

When looking up for an entry in an inlined directory, if e_value_offs is
changed underneath the filesystem by some change in the block device, it
will lead to an out-of-bounds access that KASAN detects as an UAF.

EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
loop0: detected capacity change from 2048 to 2047
==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500
Read of size 1 at addr ffff88803e91130f by task syz-executor269/5103

CPU: 0 UID: 0 PID: 5103 Comm: syz-executor269 Not tainted 6.11.0-rc4-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500
ext4_find_inline_entry+0x4be/0x5e0 fs/ext4/inline.c:1697
__ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1573
ext4_lookup_entry fs/ext4/namei.c:1727 [inline]
ext4_lookup+0x15f/0x750 fs/ext4/namei.c:1795
lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1633
filename_create+0x297/0x540 fs/namei.c:3980
do_symlinkat+0xf9/0x3a0 fs/namei.c:4587
__do_sys_symlinkat fs/namei.c:4610 [inline]
__se_sys_symlinkat fs/namei.c:4607 [inline]
__x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4607
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3e73ced469
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff4d40c258 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 0032656c69662f2e RCX: 00007f3e73ced469
RDX: 0000000020000200 RSI: 00000000ffffff9c RDI: 00000000200001c0
RBP: 0000000000000000 R08: 00007fff4d40c290 R09: 00007fff4d40c290
R10: 0023706f6f6c2f76 R11: 0000000000000246 R12: 00007fff4d40c27c
R13: 0000000000000003 R14: 431bde82d7b634db R15: 00007fff4d40c2b0
</TASK>

Calling ext4_xattr_ibody_find right after reading the inode with
ext4_get_inode_loc will lead to a check of the validity of the xattrs,
avoiding this problem.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00039}

epss

{'score': 0.0004}


Thu, 12 Dec 2024 14:45:00 +0000

Type Values Removed Values Added
Metrics threat_severity

Important

threat_severity

Moderate


Tue, 10 Dec 2024 06:45:00 +0000

Type Values Removed Values Added
Metrics threat_severity

Moderate

threat_severity

Important


Fri, 08 Nov 2024 16:00:00 +0000


Wed, 23 Oct 2024 21:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-416
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Tue, 22 Oct 2024 01:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Mon, 21 Oct 2024 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 21 Oct 2024 12:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ext4: avoid OOB when system.data xattr changes underneath the filesystem When looking up for an entry in an inlined directory, if e_value_offs is changed underneath the filesystem by some change in the block device, it will lead to an out-of-bounds access that KASAN detects as an UAF. EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. loop0: detected capacity change from 2048 to 2047 ================================================================== BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500 Read of size 1 at addr ffff88803e91130f by task syz-executor269/5103 CPU: 0 UID: 0 PID: 5103 Comm: syz-executor269 Not tainted 6.11.0-rc4-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500 ext4_find_inline_entry+0x4be/0x5e0 fs/ext4/inline.c:1697 __ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1573 ext4_lookup_entry fs/ext4/namei.c:1727 [inline] ext4_lookup+0x15f/0x750 fs/ext4/namei.c:1795 lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1633 filename_create+0x297/0x540 fs/namei.c:3980 do_symlinkat+0xf9/0x3a0 fs/namei.c:4587 __do_sys_symlinkat fs/namei.c:4610 [inline] __se_sys_symlinkat fs/namei.c:4607 [inline] __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4607 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3e73ced469 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff4d40c258 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0032656c69662f2e RCX: 00007f3e73ced469 RDX: 0000000020000200 RSI: 00000000ffffff9c RDI: 00000000200001c0 RBP: 0000000000000000 R08: 00007fff4d40c290 R09: 00007fff4d40c290 R10: 0023706f6f6c2f76 R11: 0000000000000246 R12: 00007fff4d40c27c R13: 0000000000000003 R14: 431bde82d7b634db R15: 00007fff4d40c2b0 </TASK> Calling ext4_xattr_ibody_find right after reading the inode with ext4_get_inode_loc will lead to a check of the validity of the xattrs, avoiding this problem.
Title ext4: avoid OOB when system.data xattr changes underneath the filesystem
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T09:37:48.380Z

Reserved: 2024-09-30T16:00:12.945Z

Link: CVE-2024-47701

cve-icon Vulnrichment

Updated: 2024-10-21T13:04:36.372Z

cve-icon NVD

Status : Modified

Published: 2024-10-21T12:15:06.663

Modified: 2024-11-08T16:15:25.740

Link: CVE-2024-47701

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-10-21T00:00:00Z

Links: CVE-2024-47701 - Bugzilla

cve-icon OpenCVE Enrichment

No data.