CVE-2026-93813
Estado: RecibidaAlta (7.8)—
In the Linux kernel, the following vulnerability has been resolved:
btrfs: tree-checker: validate INODE_REF's namelen
[BUG] A crafted btrfs image can trigger the following crash:
[CAUSE] TThe crafted image has the following corrupted INODE_REF item:
The itemsize matches the namelen, but the namelen is 4096, way larger than normal name length limit (BTRFS_NAME_LEN, 255).
Meanwhile the memory of the @name is only 255 byte sized, this will cause out-of-boundary access, and cause the above crash.
[FIX] Add extra namelen verification for INODE_REF, just like what we have done in ROOT_REF checks.
Now the crafted image can be rejected gracefully:
Leer descripción completaMostrar menos
BTRFS critical (device dm-2): corrupt leaf: root=5 block=30572544 slot=14 ino=259, invalid inode ref name length, has 4096 expect [1, 255] BTRFS error (device dm-2): read time tree block corruption detected on logical 30572544 mirror 2
[ Rebase, add a Link: tag, add an simple cause analyze ]
Detalles técnicos trazas, registros y código del informe original
BUG: unable to handle page fault for address: ffffd1dc42884000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
CPU: 9 UID: 0 PID: 1034 Comm: poc Not tainted 7.1.0-rc4-custom+ #383 PREEMPT(full) 46af0a92938a63be7132e0dfd71e62327c51d5c2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:memcpy+0xc/0x10
Call Trace:
<TASK>
read_extent_buffer+0xe4/0x100 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]
btrfs_get_name+0x15e/0x1e0 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]
reconnect_path+0x165/0x390
exportfs_decode_fh_raw+0x337/0x400
? drop_caches_sysctl_handler+0xb0/0xb0
</TASK>
---[ end trace 0000000000000000 ]---
RIP: 0010:memcpy+0xc/0x10
Kernel panic - not syncing: Fatal exception
item 9 key (258 INODE_REF 257) itemoff 11544 itemsize 4106
index 2 namelen 4096 name: d\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.13%
- Percentil entre todas las CVEs puntuadas: 2
- Fecha de la puntuación: 5/10/2026
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
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1499.004Application or System Exploitationimpact75 % - Impacto secundario
T1565.001Stored Data Manipulationimpact60 %
Vulnerabilidad local (AV:L/PR:L) en validación de metadatos btrfs que permite DoS por lectura fuera de límites y corrupción de datos mediante imagen crafted con namelen inválido.
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
- https://git.kernel.org/stable/c/3dc22abc21f5892406c09202fa2627196cc96967
- https://git.kernel.org/stable/c/4cb41f07685f88ec724a375883bb0c731db8f6eb
- https://git.kernel.org/stable/c/509d6a4d889e425f305461d8323a7b39ca6c121c
- https://git.kernel.org/stable/c/60078a3e25c09d9d8fba828b0d81bb33e449a1b2
- https://git.kernel.org/stable/c/8f75c19892263bc0555fba922aefe103e841e86d
- https://git.kernel.org/stable/c/eeddee090b834a7d4b6a8214d2e3739e64c7a338
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-93813",
"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:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"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": "2ede0daf01549cecf4bb0962c46dc47382047523",
"lessThan": "60078a3e25c09d9d8fba828b0d81bb33e449a1b2",
"versionType": "git"
},
{
"status": "affected",
"version": "2ede0daf01549cecf4bb0962c46dc47382047523",
"lessThan": "509d6a4d889e425f305461d8323a7b39ca6c121c",
"versionType": "git"
},
{
"status": "affected",
"version": "2ede0daf01549cecf4bb0962c46dc47382047523",
"lessThan": "4cb41f07685f88ec724a375883bb0c731db8f6eb",
"versionType": "git"
},
{
"status": "affected",
"version": "2ede0daf01549cecf4bb0962c46dc47382047523",
"lessThan": "eeddee090b834a7d4b6a8214d2e3739e64c7a338",
"versionType": "git"
},
{
"status": "affected",
"version": "2ede0daf01549cecf4bb0962c46dc47382047523",
"lessThan": "8f75c19892263bc0555fba922aefe103e841e86d",
"versionType": "git"
},
{
"status": "affected",
"version": "2ede0daf01549cecf4bb0962c46dc47382047523",
"lessThan": "3dc22abc21f5892406c09202fa2627196cc96967",
"versionType": "git"
}
],
"programFiles": [
"fs/btrfs/tree-checker.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.37"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.37",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/btrfs/tree-checker.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-24T17:17:14.763",
"references": [
{
"url": "https://git.kernel.org/stable/c/3dc22abc21f5892406c09202fa2627196cc96967",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4cb41f07685f88ec724a375883bb0c731db8f6eb",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/509d6a4d889e425f305461d8323a7b39ca6c121c",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/60078a3e25c09d9d8fba828b0d81bb33e449a1b2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8f75c19892263bc0555fba922aefe103e841e86d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/eeddee090b834a7d4b6a8214d2e3739e64c7a338",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: tree-checker: validate INODE_REF's namelen\n\n[BUG]\nA crafted btrfs image can trigger the following crash:\n\n BUG: unable to handle page fault for address: ffffd1dc42884000\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x0002) - not-present page\n CPU: 9 UID: 0 PID: 1034 Comm: poc Not tainted 7.1.0-rc4-custom+ #383 PREEMPT(full) 46af0a92938a63be7132e0dfd71e62327c51d5c2\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022\n RIP: 0010:memcpy+0xc/0x10\n Call Trace:\n <TASK>\n read_extent_buffer+0xe4/0x100 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]\n btrfs_get_name+0x15e/0x1e0 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f]\n reconnect_path+0x165/0x390\n exportfs_decode_fh_raw+0x337/0x400\n ? drop_caches_sysctl_handler+0xb0/0xb0\n </TASK>\n ---[ end trace 0000000000000000 ]---\n RIP: 0010:memcpy+0xc/0x10\n Kernel panic - not syncing: Fatal exception\n\n[CAUSE]\nTThe crafted image has the following corrupted INODE_REF item:\n\n item 9 key (258 INODE_REF 257) itemoff 11544 itemsize 4106\n \tindex 2 namelen 4096 name: d\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\\000\n\nThe itemsize matches the namelen, but the namelen is 4096, way larger\nthan normal name length limit (BTRFS_NAME_LEN, 255).\n\nMeanwhile the memory of the @name is only 255 byte sized, this will cause\nout-of-boundary access, and cause the above crash.\n\n[FIX]\nAdd extra namelen verification for INODE_REF, just like what we have\ndone in ROOT_REF checks.\n\nNow the crafted image can be rejected gracefully:\n\n BTRFS critical (device dm-2): corrupt leaf: root=5 block=30572544 slot=14 ino=259, invalid inode ref name length, has 4096 expect [1, 255]\n BTRFS error (device dm-2): read time tree block corruption detected on logical 30572544 mirror 2\n\n[ Rebase, add a Link: tag, add an simple cause analyze ]"
}
],
"lastModified": "2026-10-03T11:17:51.120",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}