CVE-2026-46020

Estado: AnalizadaAlta (7.1)—

In the Linux kernel, the following vulnerability has been resolved:

mm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp

Patch series "mm/damon/core: validate damos_quota_goal->nid".

node_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id. The node id is used for si_meminfo_node() and NODE_DATA() without proper validation. As a result, privileged users can trigger an out of bounds memory access using DAMON_SYSFS. Fix the issues.

The issue was originally reported [1] with a fix by another author. The original author announced [2] that they will stop working including the fix that was still in the review stage. Hence I'm restarting this.

Leer descripción completaMostrar menos

This patch (of 2):

Users can set damos_quota_goal->nid with arbitrary value for node_mem_{used,free}_bp. But DAMON core is using those for si_meminfo_node() without the validation of the value. This can result in out of bounds memory access. The issue can actually triggered using DAMON user-space tool (damo), like below.

Fix this issue by adding the validation of the given node. If an invalid node id is given, it returns 0% for used memory ratio, and 100% for free memory ratio.

Detalles técnicos trazas, registros y código del informe original

    $ sudo ./damo start --damos_action stat \
    	--damos_quota_goal node_mem_used_bp 50% -1 \
    	--damos_quota_interval 1s
    $ sudo dmesg
    [...]
    [   65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098

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: 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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation90 %
Impacto principalT1059 Command and Scripting Interpreterexecution75 %

Acceso local sin interacción (AV:L, PR:L, UI:N) permite escalada mediante acceso a memoria no validada en DAMON. Puede resultar en ejecución de código o DoS.

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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Privileged Account Management Limit Software Installation Behavior Prevention on Endpoint

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-125

Referencias

JSON original (NVD)

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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp\n\nPatch series \"mm/damon/core: validate damos_quota_goal->nid\".\n\nnode_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id.  The\nnode id is used for si_meminfo_node() and NODE_DATA() without proper\nvalidation.  As a result, privileged users can trigger an out of bounds\nmemory access using DAMON_SYSFS.  Fix the issues.\n\nThe issue was originally reported [1] with a fix by another author.  The\noriginal author announced [2] that they will stop working including the\nfix that was still in the review stage.  Hence I'm restarting this.\n\n\nThis patch (of 2):\n\nUsers can set damos_quota_goal->nid with arbitrary value for\nnode_mem_{used,free}_bp.  But DAMON core is using those for\nsi_meminfo_node() without the validation of the value.  This can result in\nout of bounds memory access.  The issue can actually triggered using DAMON\nuser-space tool (damo), like below.\n\n    $ sudo ./damo start --damos_action stat \\\n    \t--damos_quota_goal node_mem_used_bp 50% -1 \\\n    \t--damos_quota_interval 1s\n    $ sudo dmesg\n    [...]\n    [   65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098\n\nFix this issue by adding the validation of the given node.  If an invalid\nnode id is given, it returns 0% for used memory ratio, and 100% for free\nmemory ratio."
    }
  ],
  "lastModified": "2026-06-17T10:52:54.690",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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