{"api_version":"1","generated_at":"2026-08-01T16:47:10+00:00","cve":"CVE-2026-64458","urls":{"html":"https://cve.report/CVE-2026-64458","api":"https://cve.report/api/cve/CVE-2026-64458.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64458","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64458"},"summary":{"title":"mm/damon/ops-common: handle extreme intervals in damon_hot_score()","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-25 10:17:30","updated_at":"2026-07-25 10:17:30"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/35d4a3cf70a855b50e53189ac2f8463e20a02046","name":"https://git.kernel.org/stable/c/35d4a3cf70a855b50e53189ac2f8463e20a02046","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/76e415ea88d20f022ed5cfcf78c50e156a267e91","name":"https://git.kernel.org/stable/c/76e415ea88d20f022ed5cfcf78c50e156a267e91","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/58321b4e6e4f0f412069ab27ccdd56292757343a","name":"https://git.kernel.org/stable/c/58321b4e6e4f0f412069ab27ccdd56292757343a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a","name":"https://git.kernel.org/stable/c/ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9c8f31eaae6140ecadec0c07320498a944556de2","name":"https://git.kernel.org/stable/c/9c8f31eaae6140ecadec0c07320498a944556de2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/74fef68d521150281e36cdaa20e9e1ee3e3aa146","name":"https://git.kernel.org/stable/c/74fef68d521150281e36cdaa20e9e1ee3e3aa146","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64458","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64458","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f 58321b4e6e4f0f412069ab27ccdd56292757343a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f 74fef68d521150281e36cdaa20e9e1ee3e3aa146 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f 9c8f31eaae6140ecadec0c07320498a944556de2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f 76e415ea88d20f022ed5cfcf78c50e156a267e91 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f 35d4a3cf70a855b50e53189ac2f8463e20a02046 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.16","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.96 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.39 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.4 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64458","cve":"CVE-2026-64458","epss":"0.001800000","percentile":"0.079210000","score_date":"2026-07-28","updated_at":"2026-07-29 00:05:33"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/linux/damon.h","mm/damon/ops-common.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"58321b4e6e4f0f412069ab27ccdd56292757343a","status":"affected","version":"198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f","versionType":"git"},{"lessThan":"74fef68d521150281e36cdaa20e9e1ee3e3aa146","status":"affected","version":"198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f","versionType":"git"},{"lessThan":"ef2ae10a4582bc92b7e944181bbd2f87f3d30f3a","status":"affected","version":"198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f","versionType":"git"},{"lessThan":"9c8f31eaae6140ecadec0c07320498a944556de2","status":"affected","version":"198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f","versionType":"git"},{"lessThan":"76e415ea88d20f022ed5cfcf78c50e156a267e91","status":"affected","version":"198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f","versionType":"git"},{"lessThan":"35d4a3cf70a855b50e53189ac2f8463e20a02046","status":"affected","version":"198f0f4c58b9f481e4e51c8c70a6ab9852bbab7f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/linux/damon.h","mm/damon/ops-common.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.16"},{"lessThan":"5.16","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.96","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.39","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.96","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.39","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.4","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc3","versionStartIncluding":"5.16","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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."}],"providerMetadata":{"dateUpdated":"2026-07-25T08:51:26.072Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64458","datePublished":"2026-07-25T08:51:26.072Z","dateReserved":"2026-07-19T15:36:31.789Z","dateUpdated":"2026-07-25T08:51:26.072Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-25 10:17:30","lastModifiedDate":"2026-07-25 10:17:30","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64458","Ordinal":"1","Title":"mm/damon/ops-common: handle extreme intervals in damon_hot_score","CVE":"CVE-2026-64458","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64458","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"mm/damon/ops-common: handle extreme intervals in damon_hot_score"}]}}}