CVE-2025-71123 - Vulnerability Details

Vendors	Products
Linux	Linux Kernel

Link	Providers
https://git.kernel.org/stable/c/5bbacbbf1ca4419861dca3c6b82707c10e9c021c
https://git.kernel.org/stable/c/6e37143560e37869d51b7d9e0ac61fc48895f8a0
https://git.kernel.org/stable/c/902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc
https://git.kernel.org/stable/c/db9ee13fab0267eccf6544ee35b16c9522db9aac
https://git.kernel.org/stable/c/ee5a977b4e771cc181f39d504426dbd31ed701cc

Type	Values Removed	Values Added
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.
Title		ext4: fix string copying in parse_apply_sb_mount_options()
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/5bbacbbf1ca4419861dca3c6b82707c10e9c021c https://git.kernel.org/stable/c/6e37143560e37869d51b7d9e0ac61fc48895f8a0 https://git.kernel.org/stable/c/902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc https://git.kernel.org/stable/c/db9ee13fab0267eccf6544ee35b16c9522db9aac https://git.kernel.org/stable/c/ee5a977b4e771cc181f39d504426dbd31ed701cc

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-71123", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:30:19.654Z", "datePublished": "2026-01-14T15:06:09.246Z", "dateUpdated": "2026-01-14T15:06:09.246Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-01-14T15:06:09.246Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix string copying in parse_apply_sb_mount_options()\n\nstrscpy_pad() can't be used to copy a non-NUL-term string into a NUL-term\nstring of possibly bigger size. Commit 0efc5990bca5 (\"string.h: Introduce\nmemtostr() and memtostr_pad()\") provides additional information in that\nregard. So if this happens, the following warning is observed:\n\nstrnlen: detected buffer overflow: 65 byte read of buffer size 64\nWARNING: CPU: 0 PID: 28655 at lib/string_helpers.c:1032 __fortify_report+0x96/0xc0 lib/string_helpers.c:1032\nModules linked in:\nCPU: 0 UID: 0 PID: 28655 Comm: syz-executor.3 Not tainted 6.12.54-syzkaller-00144-g5f0270f1ba00 #0\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:__fortify_report+0x96/0xc0 lib/string_helpers.c:1032\nCall Trace:\n <TASK>\n __fortify_panic+0x1f/0x30 lib/string_helpers.c:1039\n strnlen include/linux/fortify-string.h:235 [inline]\n sized_strscpy include/linux/fortify-string.h:309 [inline]\n parse_apply_sb_mount_options fs/ext4/super.c:2504 [inline]\n __ext4_fill_super fs/ext4/super.c:5261 [inline]\n ext4_fill_super+0x3c35/0xad00 fs/ext4/super.c:5706\n get_tree_bdev_flags+0x387/0x620 fs/super.c:1636\n vfs_get_tree+0x93/0x380 fs/super.c:1814\n do_new_mount fs/namespace.c:3553 [inline]\n path_mount+0x6ae/0x1f70 fs/namespace.c:3880\n do_mount fs/namespace.c:3893 [inline]\n __do_sys_mount fs/namespace.c:4103 [inline]\n __se_sys_mount fs/namespace.c:4080 [inline]\n __x64_sys_mount+0x280/0x300 fs/namespace.c:4080\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0x64/0x140 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nSince userspace is expected to provide s_mount_opts field to be at most 63\ncharacters long with the ending byte being NUL-term, use a 64-byte buffer\nwhich matches the size of s_mount_opts, so that strscpy_pad() does its job\nproperly. Return with error if the user still managed to provide a\nnon-NUL-term string here.\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/ext4/super.c"], "versions": [{"version": "e651294218d2684302ee5ed95ccf381646f3e5b4", "lessThan": "6e37143560e37869d51b7d9e0ac61fc48895f8a0", "status": "affected", "versionType": "git"}, {"version": "01829af7656b56d83682b3491265d583d502e502", "lessThan": "902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc", "status": "affected", "versionType": "git"}, {"version": "2a0cf438320cdb783e0378570744c0ef0d83e934", "lessThan": "db9ee13fab0267eccf6544ee35b16c9522db9aac", "status": "affected", "versionType": "git"}, {"version": "8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8", "lessThan": "5bbacbbf1ca4419861dca3c6b82707c10e9c021c", "status": "affected", "versionType": "git"}, {"version": "8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8", "lessThan": "ee5a977b4e771cc181f39d504426dbd31ed701cc", "status": "affected", "versionType": "git"}, {"version": "7bf46ff83a0ef11836e38ebd72cdc5107209342d", "status": "affected", "versionType": "git"}, {"version": "b2bac84fde28fb6a88817b8b761abda17a1d300b", "status": "affected", "versionType": "git"}, {"version": "a6e94557cd05adc82fae0400f6e17745563e5412", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/ext4/super.c"], "versions": [{"version": "6.18", "status": "affected"}, {"version": "0", "lessThan": "6.18", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.160", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.120", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.64", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.3", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19-rc1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.158", "versionEndExcluding": "6.1.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.114", "versionEndExcluding": "6.6.120"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.54", "versionEndExcluding": "6.12.64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "6.18.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "6.19-rc1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.301"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.246"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17.4"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/6e37143560e37869d51b7d9e0ac61fc48895f8a0"}, {"url": "https://git.kernel.org/stable/c/902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc"}, {"url": "https://git.kernel.org/stable/c/db9ee13fab0267eccf6544ee35b16c9522db9aac"}, {"url": "https://git.kernel.org/stable/c/5bbacbbf1ca4419861dca3c6b82707c10e9c021c"}, {"url": "https://git.kernel.org/stable/c/ee5a977b4e771cc181f39d504426dbd31ed701cc"}], "title": "ext4: fix string copying in parse_apply_sb_mount_options()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix string copying in parse_apply_sb_mount_options()\n\nstrscpy_pad() can't be used to copy a non-NUL-term string into a NUL-term\nstring of possibly bigger size. Commit 0efc5990bca5 (\"string.h: Introduce\nmemtostr() and memtostr_pad()\") provides additional information in that\nregard. So if this happens, the following warning is observed:\n\nstrnlen: detected buffer overflow: 65 byte read of buffer size 64\nWARNING: CPU: 0 PID: 28655 at lib/string_helpers.c:1032 __fortify_report+0x96/0xc0 lib/string_helpers.c:1032\nModules linked in:\nCPU: 0 UID: 0 PID: 28655 Comm: syz-executor.3 Not tainted 6.12.54-syzkaller-00144-g5f0270f1ba00 #0\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:__fortify_report+0x96/0xc0 lib/string_helpers.c:1032\nCall Trace:\n <TASK>\n __fortify_panic+0x1f/0x30 lib/string_helpers.c:1039\n strnlen include/linux/fortify-string.h:235 [inline]\n sized_strscpy include/linux/fortify-string.h:309 [inline]\n parse_apply_sb_mount_options fs/ext4/super.c:2504 [inline]\n __ext4_fill_super fs/ext4/super.c:5261 [inline]\n ext4_fill_super+0x3c35/0xad00 fs/ext4/super.c:5706\n get_tree_bdev_flags+0x387/0x620 fs/super.c:1636\n vfs_get_tree+0x93/0x380 fs/super.c:1814\n do_new_mount fs/namespace.c:3553 [inline]\n path_mount+0x6ae/0x1f70 fs/namespace.c:3880\n do_mount fs/namespace.c:3893 [inline]\n __do_sys_mount fs/namespace.c:4103 [inline]\n __se_sys_mount fs/namespace.c:4080 [inline]\n __x64_sys_mount+0x280/0x300 fs/namespace.c:4080\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0x64/0x140 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nSince userspace is expected to provide s_mount_opts field to be at most 63\ncharacters long with the ending byte being NUL-term, use a 64-byte buffer\nwhich matches the size of s_mount_opts, so that strscpy_pad() does its job\nproperly. Return with error if the user still managed to provide a\nnon-NUL-term string here.\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller."}], "id": "CVE-2025-71123", "lastModified": "2026-01-14T16:25:12.057", "metrics": {}, "published": "2026-01-14T15:16:02.000", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5bbacbbf1ca4419861dca3c6b82707c10e9c021c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6e37143560e37869d51b7d9e0ac61fc48895f8a0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/902ca2356f1e3ec5355c5808ad5d3f9d0095b0cc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/db9ee13fab0267eccf6544ee35b16c9522db9aac"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ee5a977b4e771cc181f39d504426dbd31ed701cc"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

Metrics

Affected Vendors & Products

Metrics

Affected Vendors & Products

JSON object

JSON object

JSON object

JSON object

JSON object