{"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"}}}}