CVE-2026-98243
In the Linux kernel, the following vulnerability has been resolved:
dma-buf/dma-fence: fix checking signaling bit for timeline and driver name v3
The patch "dma-buf: dma-fence: Fix potential NULL pointer dereference" changed the check to test for the ops pointer instead of the signaled bit to avoid a potential NULL dereference when the ops pointer has been cleared.
The problem is now that the ops pointer is cleared only when neither the release nor the wait callback is implemented and this isn't true for a lot of dma_fence implementations yet. So those implementations lost the RCU protection after signaling of the returned string resulting in potential use after free.
Leer descripción completaMostrar menos
Add the signaling check additional to the ops pointer check so that we have both the protection against NULL dereference as well as the RCU protection after signaling for the returned string.
v2: improve comments to note RCU protection and explain why we check both signaling state and ops pointer v3: some comment improvements suggested by Philip
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- Puntuación base: 7.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- 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
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1499.004Application or System Exploitationimpact75 %
Vulnerabilidad local (AV:L/PR:L) de kernel Linux que causa use-after-free, permitiendo denegación de servicio o corrupción de memoria con privilegios de usuario.
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-2026-98243",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.1,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.2,
"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": "035219a760edb35ae9a9e96beba7f122e26a997b",
"lessThan": "a4db25b8949d6ff9c1a685a1273a015e8bab29db",
"versionType": "git"
},
{
"status": "affected",
"version": "035219a760edb35ae9a9e96beba7f122e26a997b",
"lessThan": "3ed11c671ff7ec58c8fd96410233c677df23f407",
"versionType": "git"
},
{
"status": "affected",
"version": "15ecfdf0ef6f6d874d0a26690d300857b39ebfd0",
"versionType": "git"
},
{
"status": "affected",
"version": "7.1.5",
"lessThan": "7.2",
"versionType": "semver"
}
],
"programFiles": [
"drivers/dma-buf/dma-fence.c",
"include/linux/dma-fence.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "7.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "7.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc4",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/dma-buf/dma-fence.c",
"include/linux/dma-fence.h"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-06T09:18:12.383",
"references": [
{
"url": "https://git.kernel.org/stable/c/3ed11c671ff7ec58c8fd96410233c677df23f407",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a4db25b8949d6ff9c1a685a1273a015e8bab29db",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndma-buf/dma-fence: fix checking signaling bit for timeline and driver name v3\n\nThe patch \"dma-buf: dma-fence: Fix potential NULL pointer dereference\"\nchanged the check to test for the ops pointer instead of the signaled\nbit to avoid a potential NULL dereference when the ops pointer has been\ncleared.\n\nThe problem is now that the ops pointer is cleared only when neither the\nrelease nor the wait callback is implemented and this isn't true for a lot\nof dma_fence implementations yet. So those implementations lost the RCU\nprotection after signaling of the returned string resulting in potential\nuse after free.\n\nAdd the signaling check additional to the ops pointer check so that we\nhave both the protection against NULL dereference as well as the RCU\nprotection after signaling for the returned string.\n\nv2: improve comments to note RCU protection and explain why we check\n both signaling state and ops pointer\nv3: some comment improvements suggested by Philip"
}
],
"lastModified": "2026-10-07T07:17:06.120",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}