{"api_version":"1","generated_at":"2026-08-22T21:11:56+00:00","cve":"CVE-2026-74645","urls":{"html":"https://cve.report/CVE-2026-74645","api":"https://cve.report/api/cve/CVE-2026-74645.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74645","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74645"},"summary":{"title":"mm/damon/lru_sort: error out for >10000 active_mem_bp","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/lru_sort: error out for >10000 active_mem_bp\n\ndamos_quota_score() can trigger division by zero if the target value is\nzero.  DAMON_LRU_SORT lets users set the target value for the hot memory\nscheme via active_mem_bp parameter.  It avoids setting it as the target\nvalue if the parameter value is zero.  However, it also sets the cold\nmemory scheme with a target value that is calculated as '10000 -\nactive_mem_bp + 2'.  Hence, if a user sets active_mem_bp 10002, the cold\nmemory scheme's quota goal target value can be zero.  As a result,\ndivision by zero can be triggered.  Fix by returning an error when the\nuser tries to start DAMON with >10000 active_mem_bp parameter value.\n\nIt makes no sense to set active_mem_bp with 10002.  It also requires\nmodule parameters write permission to reproduce the issue.  That said, the\nconsequence is quite bad.\n\nOne reliable way to reproduce the issue is like below:\n\n    # cd /sys/module/damon_lru_sort/parameters\n    # echo 1000 > wmarks_high\n    # echo 995 > wmarks_mid\n    # echo 0 > wmarks_low\n    # echo 10002 > active_mem_bp\n    # echo Y > enabled\n    # dmesg -w\n    [...]\n    [  597.421247] Oops: divide error: 0000 [#1] SMP NOPTI\n    [  597.428848] RIP: 0010:damos_quota_score+0x6f/0x480\n\nThis issue was discovered [1] by Sashiko.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-22 16:16:37","updated_at":"2026-08-22 16:16:37"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/06befa61c427e74319781e6f35a364cfc32dbae8","name":"https://git.kernel.org/stable/c/06befa61c427e74319781e6f35a364cfc32dbae8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e7e5e5e0dfe2ea171044c24c263efae4ee882b3f","name":"https://git.kernel.org/stable/c/e7e5e5e0dfe2ea171044c24c263efae4ee882b3f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74645","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74645","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 40d98d31cd7060228e03303c5c34ae7101020416 e7e5e5e0dfe2ea171044c24c263efae4ee882b3f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 40d98d31cd7060228e03303c5c34ae7101020416 06befa61c427e74319781e6f35a364cfc32dbae8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.0","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.9 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["mm/damon/lru_sort.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"e7e5e5e0dfe2ea171044c24c263efae4ee882b3f","status":"affected","version":"40d98d31cd7060228e03303c5c34ae7101020416","versionType":"git"},{"lessThan":"06befa61c427e74319781e6f35a364cfc32dbae8","status":"affected","version":"40d98d31cd7060228e03303c5c34ae7101020416","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["mm/damon/lru_sort.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.0"},{"lessThan":"7.0","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.9","versionStartIncluding":"7.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"7.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/lru_sort: error out for >10000 active_mem_bp\n\ndamos_quota_score() can trigger division by zero if the target value is\nzero.  DAMON_LRU_SORT lets users set the target value for the hot memory\nscheme via active_mem_bp parameter.  It avoids setting it as the target\nvalue if the parameter value is zero.  However, it also sets the cold\nmemory scheme with a target value that is calculated as '10000 -\nactive_mem_bp + 2'.  Hence, if a user sets active_mem_bp 10002, the cold\nmemory scheme's quota goal target value can be zero.  As a result,\ndivision by zero can be triggered.  Fix by returning an error when the\nuser tries to start DAMON with >10000 active_mem_bp parameter value.\n\nIt makes no sense to set active_mem_bp with 10002.  It also requires\nmodule parameters write permission to reproduce the issue.  That said, the\nconsequence is quite bad.\n\nOne reliable way to reproduce the issue is like below:\n\n    # cd /sys/module/damon_lru_sort/parameters\n    # echo 1000 > wmarks_high\n    # echo 995 > wmarks_mid\n    # echo 0 > wmarks_low\n    # echo 10002 > active_mem_bp\n    # echo Y > enabled\n    # dmesg -w\n    [...]\n    [  597.421247] Oops: divide error: 0000 [#1] SMP NOPTI\n    [  597.428848] RIP: 0010:damos_quota_score+0x6f/0x480\n\nThis issue was discovered [1] by Sashiko."}],"providerMetadata":{"dateUpdated":"2026-08-22T15:32:22.645Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/e7e5e5e0dfe2ea171044c24c263efae4ee882b3f"},{"url":"https://git.kernel.org/stable/c/06befa61c427e74319781e6f35a364cfc32dbae8"}],"title":"mm/damon/lru_sort: error out for >10000 active_mem_bp","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74645","datePublished":"2026-08-22T15:32:22.645Z","dateReserved":"2026-08-15T05:44:03.923Z","dateUpdated":"2026-08-22T15:32:22.645Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-22 16:16:37","lastModifiedDate":"2026-08-22 16:16:37","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74645","Ordinal":"1","Title":"mm/damon/lru_sort: error out for >10000 active_mem_bp","CVE":"CVE-2026-74645","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74645","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/lru_sort: error out for >10000 active_mem_bp\n\ndamos_quota_score() can trigger division by zero if the target value is\nzero.  DAMON_LRU_SORT lets users set the target value for the hot memory\nscheme via active_mem_bp parameter.  It avoids setting it as the target\nvalue if the parameter value is zero.  However, it also sets the cold\nmemory scheme with a target value that is calculated as '10000 -\nactive_mem_bp + 2'.  Hence, if a user sets active_mem_bp 10002, the cold\nmemory scheme's quota goal target value can be zero.  As a result,\ndivision by zero can be triggered.  Fix by returning an error when the\nuser tries to start DAMON with >10000 active_mem_bp parameter value.\n\nIt makes no sense to set active_mem_bp with 10002.  It also requires\nmodule parameters write permission to reproduce the issue.  That said, the\nconsequence is quite bad.\n\nOne reliable way to reproduce the issue is like below:\n\n    # cd /sys/module/damon_lru_sort/parameters\n    # echo 1000 > wmarks_high\n    # echo 995 > wmarks_mid\n    # echo 0 > wmarks_low\n    # echo 10002 > active_mem_bp\n    # echo Y > enabled\n    # dmesg -w\n    [...]\n    [  597.421247] Oops: divide error: 0000 [#1] SMP NOPTI\n    [  597.428848] RIP: 0010:damos_quota_score+0x6f/0x480\n\nThis issue was discovered [1] by Sashiko.","Type":"Description","Title":"mm/damon/lru_sort: error out for >10000 active_mem_bp"}]}}}