CVE-2026-64458
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/ops-common: handle extreme intervals in damon_hot_score()
Fix three issues in damon_hot_score() that comes from wrong handling of extreme (zero or too high) monitoring intervals user setup.
When the user sets sampling interval zero, damon_max_nr_accesses(), which is called from damon_hot_score(), causes a divide-by-zero. Needless to say, it is a problem.
When the user sets the aggregation interval zero, the function returns zero. It is wrong, since the real maximum nr_acceses in the setup should be one. Worse yet, it can cause another divide-by-zero from its caller, damon_hot_score(), since it uses damon_max_nr_accesses() return value as a denominator.
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When the user sets the aggregation interval very high, damon_hot_score() could return a value out of [0, DAMOS_MAX_SCORE] range. Since the return value is used as an index to the regions_score_histogram array, which is DAMOS_MAX_SCORE+1 size, it causes out of bounds array access.
The issues can be relatively easily reproduced like below. The sysfs write permission is required, though.
Fix the divide-by-zero intervals problems by explicitly handling the zero intervals in damon_max_nr_accesses(). Fix the out-of-bound array access by applying [0, DAMOS_MAX_SCORE] bounds before returning from damon_hot_score().
The issue was discovered [1] by Sashiko.
Detalles técnicos trazas, registros y código del informe original
# ./damo start --damos_action lru_prio --damos_quota_space 100M \
--damos_quota_interval 1s
# cd /sys/kernel/mm/damon/admin/kdamonds/0
# echo 0 > contexts/0/monitoring_attrs/intervals/sample_us
# echo 0 > contexts/0/monitoring_attrs/intervals/aggr_us
# echo commit > state
# dmesg
[...]
[ 131.329762] Oops: divide error: 0000 [#1] SMP NOPTI
[...]
[ 131.336089] RIP: 0010:damon_hot_score+0x27/0xd0
[...]CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.18%
- Percentil entre todas las CVEs puntuadas: 7
- Fecha de la puntuación: 3/10/2026
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).
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/35d4a3cf70a855b50e53189ac2f8463e20a02046
- https://git.kernel.org/stable/c/58321b4e6e4f0f412069ab27ccdd56292757343a
- https://git.kernel.org/stable/c/74fef68d521150281e36cdaa20e9e1ee3e3aa146
- https://git.kernel.org/stable/c/76e415ea88d20f022ed5cfcf78c50e156a267e91
- https://git.kernel.org/stable/c/9c8f31eaae6140ecadec0c07320498a944556de2
- https://git.kernel.org/stable/c/ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64458",
"cveTags": [],
"metrics": {},
"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": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f",
"lessThan": "58321b4e6e4f0f412069ab27ccdd56292757343a",
"versionType": "git"
},
{
"status": "affected",
"version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f",
"lessThan": "74fef68d521150281e36cdaa20e9e1ee3e3aa146",
"versionType": "git"
},
{
"status": "affected",
"version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f",
"lessThan": "ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a",
"versionType": "git"
},
{
"status": "affected",
"version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f",
"lessThan": "9c8f31eaae6140ecadec0c07320498a944556de2",
"versionType": "git"
},
{
"status": "affected",
"version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f",
"lessThan": "76e415ea88d20f022ed5cfcf78c50e156a267e91",
"versionType": "git"
},
{
"status": "affected",
"version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f",
"lessThan": "35d4a3cf70a855b50e53189ac2f8463e20a02046",
"versionType": "git"
}
],
"programFiles": [
"include/linux/damon.h",
"mm/damon/ops-common.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/damon.h",
"mm/damon/ops-common.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-25T10:17:30.943",
"references": [
{
"url": "https://git.kernel.org/stable/c/35d4a3cf70a855b50e53189ac2f8463e20a02046",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/58321b4e6e4f0f412069ab27ccdd56292757343a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/74fef68d521150281e36cdaa20e9e1ee3e3aa146",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/76e415ea88d20f022ed5cfcf78c50e156a267e91",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9c8f31eaae6140ecadec0c07320498a944556de2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/ops-common: handle extreme intervals in damon_hot_score()\n\nFix three issues in damon_hot_score() that comes from wrong handling of\nextreme (zero or too high) monitoring intervals user setup.\n\nWhen the user sets sampling interval zero, damon_max_nr_accesses(), which\nis called from damon_hot_score(), causes a divide-by-zero. Needless to\nsay, it is a problem.\n\nWhen the user sets the aggregation interval zero, the function returns\nzero. It is wrong, since the real maximum nr_acceses in the setup should\nbe one. Worse yet, it can cause another divide-by-zero from its caller,\ndamon_hot_score(), since it uses damon_max_nr_accesses() return value as a\ndenominator.\n\nWhen the user sets the aggregation interval very high, damon_hot_score()\ncould return a value out of [0, DAMOS_MAX_SCORE] range. Since the return\nvalue is used as an index to the regions_score_histogram array, which is\nDAMOS_MAX_SCORE+1 size, it causes out of bounds array access.\n\nThe issues can be relatively easily reproduced like below. The sysfs\nwrite permission is required, though.\n\n # ./damo start --damos_action lru_prio --damos_quota_space 100M \\\n --damos_quota_interval 1s\n # cd /sys/kernel/mm/damon/admin/kdamonds/0\n # echo 0 > contexts/0/monitoring_attrs/intervals/sample_us\n # echo 0 > contexts/0/monitoring_attrs/intervals/aggr_us\n # echo commit > state\n # dmesg\n [...]\n [ 131.329762] Oops: divide error: 0000 [#1] SMP NOPTI\n [...]\n [ 131.336089] RIP: 0010:damon_hot_score+0x27/0xd0\n [...]\n\nFix the divide-by-zero intervals problems by explicitly handling the zero\nintervals in damon_max_nr_accesses(). Fix the out-of-bound array access\nby applying [0, DAMOS_MAX_SCORE] bounds before returning from\ndamon_hot_score().\n\nThe issue was discovered [1] by Sashiko."
}
],
"lastModified": "2026-08-17T05:17:50.980",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}