CVE-2025-71123

HIGH EPSS 4.8%
Published Jan 14, 20265mo ago · Modified Jun 17, 20262w ago
7.8 CVSS 3.1
High
Find Similar
Published Jan 14, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix string copying in parse_apply_sb_mount_options() strscpy_pad() can't be used to copy a non-NUL-term string into a NUL-term string of possibly bigger size. Commit 0efc5990bca5 ("string.h: Introduce memtostr() and memtostr_pad()") provides additional information in that regard. So if this happens, the following warning is observed: strnlen: detected buffer overflow: 65 byte read of buffer size 64 WARNING: CPU: 0 PID: 28655 at lib/string_helpers.c:1032 __fortify_report+0x96/0xc0 lib/string_helpers.c:1032 Modules linked in: CPU: 0 UID: 0 PID: 28655 Comm: syz-executor.3 Not tainted 6.12.54-syzkaller-00144-g5f0270f1ba00 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__fortify_report+0x96/0xc0 lib/string_helpers.c:1032 Call Trace: <TASK> __fortify_panic+0x1f/0x30 lib/string_helpers.c:1039 strnlen include/linux/fortify-string.h:235 [inline] sized_strscpy include/linux/fortify-string.h:309 [inline] parse_apply_sb_mount_options fs/ext4/super.c:2504 [inline] __ext4_fill_super fs/ext4/super.c:5261 [inline] ext4_fill_super+0x3c35/0xad00 fs/ext4/super.c:5706 get_tree_bdev_flags+0x387/0x620 fs/super.c:1636 vfs_get_tree+0x93/0x380 fs/super.c:1814 do_new_mount fs/namespace.c:3553 [inline] path_mount+0x6ae/0x1f70 fs/namespace.c:3880 do_mount fs/namespace.c:3893 [inline] __do_sys_mount fs/namespace.c:4103 [inline] __se_sys_mount fs/namespace.c:4080 [inline] __x64_sys_mount+0x280/0x300 fs/namespace.c:4080 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x64/0x140 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e Since userspace is expected to provide s_mount_opts field to be at most 63 characters long with the ending byte being NUL-term, use a 64-byte buffer which matches the size of s_mount_opts, so that strscpy_pad() does its job properly. Return with error if the user still managed to provide a non-NUL-term string here. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
4.8% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 16

VendorProductVersionRange
linuxlinux_kernel*≥5.4.301  –  <5.5
linuxlinux_kernel*≥5.10.246  –  <5.10.248
linuxlinux_kernel*≥6.1.158  –  <6.1.160
linuxlinux_kernel*≥6.6.114  –  <6.6.120
linuxlinux_kernel*≥6.12.54  –  <6.12.64
linuxlinux_kernel*≥6.17.4  –  <6.18
linuxlinux_kernel*≥6.18.1  –  <6.18.3
linuxlinux_kernel6.18any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any
linuxlinux_kernel6.19any

References 6

  • git.kernel.org https://git.kernel.org/stable/c/52ac96c4a2dd7bc47666000440b0602d9742e820
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5bbacbbf1ca4419861dca3c6b82707c10e9c021c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6e37143560e37869d51b7d9e0ac61fc48895f8a0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/db9ee13fab0267eccf6544ee35b16c9522db9aac
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ee5a977b4e771cc181f39d504426dbd31ed701cc
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/52ac96c4a2dd7bc47666000440b0602d9742e820
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5bbacbbf1ca4419861dca3c6b82707c10e9c021c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6e37143560e37869d51b7d9e0ac61fc48895f8a0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/db9ee13fab0267eccf6544ee35b16c9522db9aac
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ee5a977b4e771cc181f39d504426dbd31ed701cc
    Patch