cbcvebase.
CVE-2025-71123
published 2026-01-14

CVE-2025-71123: 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…

PriorityP340high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.15%
4.9th percentile
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: __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

Affected

70 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.162-1 (bookworm)linux 6.1.162-1 (bookworm)
debianlinux-6.1< linux 6.1.162-1 (bookworm)linux 6.1.162-1 (bookworm)
linuxlinux
linuxlinux
linuxlinux
linuxlinux>= 01829af7656b56d83682b3491265d583d502e502 < 902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc
linuxlinux>= 2a0cf438320cdb783e0378570744c0ef0d83e934 < db9ee13fab0267eccf6544ee35b16c9522db9aacdb9ee13fab0267eccf6544ee35b16c9522db9aac
linuxlinux>= 5.10.246 < 5.10.2485.10.248
linuxlinux>= 5.4.301 < 5.55.5
linuxlinux>= 6.1.158 < 6.1.1606.1.160
linuxlinux>= 6.12.54 < 6.12.646.12.64
linuxlinux>= 6.17.4 < 6.186.18
linuxlinux>= 6.6.114 < 6.6.1206.6.120
linuxlinux>= 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 < 5bbacbbf1ca4419861dca3c6b82707c10e9c021c5bbacbbf1ca4419861dca3c6b82707c10e9c021c
linuxlinux>= 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 < ee5a977b4e771cc181f39d504426dbd31ed701ccee5a977b4e771cc181f39d504426dbd31ed701cc
linuxlinux>= b2bac84fde28fb6a88817b8b761abda17a1d300b < 52ac96c4a2dd7bc47666000440b0602d9742e82052ac96c4a2dd7bc47666000440b0602d9742e820
linuxlinux>= e651294218d2684302ee5ed95ccf381646f3e5b4 < 6e37143560e37869d51b7d9e0ac61fc48895f8a06e37143560e37869d51b7d9e0ac61fc48895f8a0
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_redhat7.8HIGH
vendor_ubuntu6.4MEDIUM
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.