CVE-2026-90321
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate inline xattrs during inode block validation
Patch series "ocfs2: validate xattr entry bounds", v7.
This series validates OCFS2 xattr entry name/value bounds when xattr metadata is read and validated, before getxattr() or listxattr() can walk out-of-range entry arrays or offsets from corrupted metadata.
This patch (of 2):
ocfs2_validate_inode_block() verifies a dinode before OCFS2 users walk metadata from it, but inline xattr metadata is still checked only in operation-specific consumers. The existing ibody lookup helper validates inline header placement and entry count, but inode block validation does not reject entry name/value bounds.
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Add a flat xattr entry validator and call it from inode block validation for inline xattrs. Keep the operation paths on their existing header/count lookup checks; the full entry bounds check now runs when the inode block is validated at read time.
Reject corrupted inline xattr metadata before ocfs2_xattr_ibody_get() or listxattr() can walk past the inline storage.
Detalles técnicos trazas, registros y código del informe original
Validation reproduced this kernel report: BUG: KASAN: use-after-free in ocfs2_xattr_find_entry+0x5a/0x170 Read of size 2 at addr ffff8881242a2000 by task python3/529 Call Trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 kasan_report+0xe0/0x110 ocfs2_xattr_find_entry+0x5a/0x170 ocfs2_xattr_get_nolock+0x20a/0x820 ocfs2_xattr_get+0x10c/0x1e0 __vfs_getxattr+0xe2/0x130 vfs_getxattr+0x185/0x1b0
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.17%
- Percentil entre todas las CVEs puntuadas: 6
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1203Exploitation for Client Executionexecution85 % - Impacto principal
T1005Data from Local Systemcollection75 % - Impacto secundario
T1499.004Application or System Exploitationimpact70 %
Vulnerabilidad local (AV:L, PR:N, UI:R) en validación de xattr que permite lectura fuera de límites (use-after-free) y DoS via corrupción de metadatos en OCFS2 sin validación previa.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-90321",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "cf1d6c763fbcb115263114302485ad17e7933d87",
"lessThan": "3fd45b24879fa4885b66a582a6e47eda67f11310",
"versionType": "git"
},
{
"status": "affected",
"version": "cf1d6c763fbcb115263114302485ad17e7933d87",
"lessThan": "8914a3330b72378136c2c02d6328a826f6abdad7",
"versionType": "git"
}
],
"programFiles": [
"fs/ocfs2/inode.c",
"fs/ocfs2/xattr.c",
"fs/ocfs2/xattr.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.28"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.28",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/ocfs2/inode.c",
"fs/ocfs2/xattr.c",
"fs/ocfs2/xattr.h"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-17T17:17:30.067",
"references": [
{
"url": "https://git.kernel.org/stable/c/3fd45b24879fa4885b66a582a6e47eda67f11310",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8914a3330b72378136c2c02d6328a826f6abdad7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate inline xattrs during inode block validation\n\nPatch series \"ocfs2: validate xattr entry bounds\", v7.\n\nThis series validates OCFS2 xattr entry name/value bounds when xattr\nmetadata is read and validated, before getxattr() or listxattr() can walk\nout-of-range entry arrays or offsets from corrupted metadata.\n\n\nThis patch (of 2):\n\nocfs2_validate_inode_block() verifies a dinode before OCFS2 users walk\nmetadata from it, but inline xattr metadata is still checked only in\noperation-specific consumers. The existing ibody lookup helper validates\ninline header placement and entry count, but inode block validation does\nnot reject entry name/value bounds.\n\nAdd a flat xattr entry validator and call it from inode block validation\nfor inline xattrs. Keep the operation paths on their existing\nheader/count lookup checks; the full entry bounds check now runs when the\ninode block is validated at read time.\n\nReject corrupted inline xattr metadata before ocfs2_xattr_ibody_get() or\nlistxattr() can walk past the inline storage.\n\nValidation reproduced this kernel report:\nBUG: KASAN: use-after-free in ocfs2_xattr_find_entry+0x5a/0x170\nRead of size 2 at addr ffff8881242a2000 by task python3/529\nCall Trace:\n dump_stack_lvl+0x66/0xa0\n print_report+0xce/0x630\n kasan_report+0xe0/0x110\n ocfs2_xattr_find_entry+0x5a/0x170\n ocfs2_xattr_get_nolock+0x20a/0x820\n ocfs2_xattr_get+0x10c/0x1e0\n __vfs_getxattr+0xe2/0x130\n vfs_getxattr+0x185/0x1b0"
}
],
"lastModified": "2026-09-18T18:17:53.710",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}