CVE-2026-74359 (GCVE-0-2026-74359)
Vulnerability from cvelistv5
Published
2026-08-15 05:58
Modified
2026-08-17 05:46
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
configfs_lookup(): don't leave ->s_dentry dangling on failure
Normally ->s_dentry is cleared when dentry it's pointing to becomes
negative (on eviction, realistically). However, that only happens
if dentry gets to be positive in the first place; in case of inode
allocation failure dentry never becomes positive, so ->d_iput()
is not called at all.
We do part of what normally would've been done by configfs_d_iput()
(dropping the reference to configfs_dirent) manually, but we do
not clear ->s_dentry there. Sloppy as it is, it does not matter in
case of configfs_create_{dir,link}() - there configfs_dirent does
not survive dropping the sole reference to it.
However, for configfs_lookup() it *does* survive, with a dangling
pointer to soon to be freed dentry sitting it its ->s_dentry.
Subsequent getdents(2) in that directory will end up dereferencing
that pointer in order to pick the inode number. Use after free...
This is the minimal fix; the right approach is to set the linkage
between dentry and configfs_dirent only after we know that we have
an inode, but that takes more surgery and the bug had been there
since 2006, so...
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d Version: 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d Version: 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d Version: 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d Version: 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d Version: 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d Version: 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/configfs/dir.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"version": "3d0f89bb169482d26d5aa4e82e763077e7e9bc4d",
"versionType": "git"
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{
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"versionType": "git"
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{
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{
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]
},
{
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"product": "Linux",
"programFiles": [
"fs/configfs/dir.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.16"
},
{
"lessThan": "2.6.16",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.212",
"versionStartIncluding": "2.6.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "2.6.16",
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},
{
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{
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{
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{
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},
{
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"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nconfigfs_lookup(): don\u0027t leave -\u003es_dentry dangling on failure\n\nNormally -\u003es_dentry is cleared when dentry it\u0027s pointing to becomes\nnegative (on eviction, realistically). However, that only happens\nif dentry gets to be positive in the first place; in case of inode\nallocation failure dentry never becomes positive, so -\u003ed_iput()\nis not called at all.\n\nWe do part of what normally would\u0027ve been done by configfs_d_iput()\n(dropping the reference to configfs_dirent) manually, but we do\nnot clear -\u003es_dentry there. Sloppy as it is, it does not matter in\ncase of configfs_create_{dir,link}() - there configfs_dirent does\nnot survive dropping the sole reference to it.\n\nHowever, for configfs_lookup() it *does* survive, with a dangling\npointer to soon to be freed dentry sitting it its -\u003es_dentry.\n\nSubsequent getdents(2) in that directory will end up dereferencing\nthat pointer in order to pick the inode number. Use after free...\n\nThis is the minimal fix; the right approach is to set the linkage\nbetween dentry and configfs_dirent only after we know that we have\nan inode, but that takes more surgery and the bug had been there\nsince 2006, so..."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is reached only via local VFS syscalls (openat/stat on a configfs attribute and getdents on its parent) against /sys/kernel/config; configfs is not exposed through network-facing kernel services such as ksmbd, nfsd, or the TCP/IP stack.\nAC:L - Exploitation is a deterministic error-path bug, not a race: inode allocation failure in configfs_lookup() leaves sd-\u003es_dentry dangling and a follow-up getdents reliably dereferences it; the attacker can force ENOMEM by applying memory pressure they control.\nPR:L - Default configfs modes (0755 directories, 0644 attributes) let any local user read/list kernel-registered subsystem trees (e.g. nvmet, usb_gadget) without init-namespace root; mkdir/write still need admin, but triggering lookup on existing unpinned attributes does not.\nUI:N - No victim interaction is required beyond the attacker issuing their own syscalls on configfs paths; configfs is mounted at boot under /sys/kernel/config and exploitation does not depend on another user mounting or opening files.\nS:U - The use-after-free corrupts kernel heap memory and enables local privilege escalation within the same kernel security domain; it does not cross VM, IOMMU, or sandbox boundaries.\nC:H - configfs_readdir() reads d_inode() through a dangling sd-\u003es_dentry after failed lookup, giving a slab use-after-free read primitive on freed dentry/inode memory that can disclose kernel data or pointers via heap reuse.\nI:H - Reclaimed dentry/inode slabs let an attacker shape freed-object contents and convert the dangling pointer into arbitrary kernel writes and control-flow hijack, consistent with standard UAF exploitation of VFS objects.\nA:H - Dereferencing the freed dentry during getdents causes kernel oops/panic (as described in the fix); the UAF is repeatable and can deny service even when full exploitation is not attempted."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:46:19.411Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/3e83b2203aa59bd279e4f677ec793d49dc9d019e"
},
{
"url": "https://git.kernel.org/stable/c/b6e9c82522ddaa3ac0706b295ff4a71975d4f883"
},
{
"url": "https://git.kernel.org/stable/c/eee07d769da5ac4e4f7bd0bc17828646a318d499"
},
{
"url": "https://git.kernel.org/stable/c/9c747dcee164ead300de90550ad9e4122f0d1bbb"
},
{
"url": "https://git.kernel.org/stable/c/c3b073a209a9baa691b744318ac929fecdd8847c"
},
{
"url": "https://git.kernel.org/stable/c/57088b06109f3222963c639d8d743f42c2899b13"
},
{
"url": "https://git.kernel.org/stable/c/10da12d352b7b2bb330a8609fdda9a58bf0e9856"
}
],
"title": "configfs_lookup(): don\u0027t leave -\u003es_dentry dangling on failure",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74359",
"datePublished": "2026-08-15T05:58:43.456Z",
"dateReserved": "2026-08-15T05:44:03.887Z",
"dateUpdated": "2026-08-17T05:46:19.411Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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