{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64458", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.789Z", "datePublished": "2026-07-25T08:51:26.072Z", "dateUpdated": "2026-08-17T04:56:02.857Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:56:02.857Z" }, "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." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/damon.h", "mm/damon/ops-common.c" ], "versions": [ { "version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f", "lessThan": "58321b4e6e4f0f412069ab27ccdd56292757343a", "status": "affected", "versionType": "git" }, { "version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f", "lessThan": "74fef68d521150281e36cdaa20e9e1ee3e3aa146", "status": "affected", "versionType": "git" }, { "version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f", "lessThan": "ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a", "status": "affected", "versionType": "git" }, { "version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f", "lessThan": "9c8f31eaae6140ecadec0c07320498a944556de2", "status": "affected", "versionType": "git" }, { "version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f", "lessThan": "76e415ea88d20f022ed5cfcf78c50e156a267e91", "status": "affected", "versionType": "git" }, { "version": "198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f", "lessThan": "35d4a3cf70a855b50e53189ac2f8463e20a02046", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/damon.h", "mm/damon/ops-common.c" ], "versions": [ { "version": "5.16", "status": "affected" }, { "version": "0", "lessThan": "5.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/58321b4e6e4f0f412069ab27ccdd56292757343a" }, { "url": "https://git.kernel.org/stable/c/74fef68d521150281e36cdaa20e9e1ee3e3aa146" }, { "url": "https://git.kernel.org/stable/c/ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a" }, { "url": "https://git.kernel.org/stable/c/9c8f31eaae6140ecadec0c07320498a944556de2" }, { "url": "https://git.kernel.org/stable/c/76e415ea88d20f022ed5cfcf78c50e156a267e91" }, { "url": "https://git.kernel.org/stable/c/35d4a3cf70a855b50e53189ac2f8463e20a02046" } ], "title": "mm/damon/ops-common: handle extreme intervals in damon_hot_score()", "x_generator": { "engine": "bippy-1.2.0" } } } }