{"id":"CVE-2026-46020","state":"PUBLISHED","title":"mm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp\n\nPatch series \"mm/damon/core: validate damos_quota_goal->nid\".\n\nnode_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id.  The\nnode id is used for si_meminfo_node() and NODE_DATA() without proper\nvalidation.  As a result, privileged users can trigger an out of bounds\nmemory access using DAMON_SYSFS.  Fix the issues.\n\nThe issue was originally reported [1] with a fix by another author.  The\noriginal author announced [2] that they will stop working including the\nfix that was still in the review stage.  Hence I'm restarting this.\n\n\nThis patch (of 2):\n\nUsers can set damos_quota_goal->nid with arbitrary value for\nnode_mem_{used,free}_bp.  But DAMON core is using those for\nsi_meminfo_node() without the validation of the value.  This can result in\nout of bounds memory access.  The issue can actually triggered using DAMON\nuser-space tool (damo), like below.\n\n    $ sudo ./damo start --damos_action stat \\\n    \t--damos_quota_goal node_mem_used_bp 50% -1 \\\n    \t--damos_quota_interval 1s\n    $ sudo dmesg\n    [...]\n    [   65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098\n\nFix this issue by adding the validation of the given node.  If an invalid\nnode id is given, it returns 0% for used memory ratio, and 100% for free\nmemory ratio.","publishedAt":"2026-05-27T12:56:21.920Z","updatedAt":"2026-06-14T17:48:26.041Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0e1c773b501f33437d87b72c7d26080361e224b1","status":"affected","lessThan":"b09958e235f2b9cd3898b85a8529172afa80d212","versionType":"git"},{"version":"0e1c773b501f33437d87b72c7d26080361e224b1","status":"affected","lessThan":"bcad74078708f2330a45b55358ebc38f8f4b1127","versionType":"git"},{"version":"0e1c773b501f33437d87b72c7d26080361e224b1","status":"affected","lessThan":"40250b2dded0604a112be605f3828700d80ad7c2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/damon/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.27","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.4","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/damon/core.c"]}],"references":["https://git.kernel.org/stable/c/b09958e235f2b9cd3898b85a8529172afa80d212","https://git.kernel.org/stable/c/bcad74078708f2330a45b55358ebc38f8f4b1127","https://git.kernel.org/stable/c/40250b2dded0604a112be605f3828700d80ad7c2"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46020.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46020","state":"PUBLISHED","datePublished":"2026-05-27T12:56:21.920Z","dateUpdated":"2026-06-14T17:48:26.041Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.092Z"},"containers":{"cna":{"title":"mm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp\n\nPatch series \"mm/damon/core: validate damos_quota_goal->nid\".\n\nnode_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id.  The\nnode id is used for si_meminfo_node() and NODE_DATA() without proper\nvalidation.  As a result, privileged users can trigger an out of bounds\nmemory access using DAMON_SYSFS.  Fix the issues.\n\nThe issue was originally reported [1] with a fix by another author.  The\noriginal author announced [2] that they will stop working including the\nfix that was still in the review stage.  Hence I'm restarting this.\n\n\nThis patch (of 2):\n\nUsers can set damos_quota_goal->nid with arbitrary value for\nnode_mem_{used,free}_bp.  But DAMON core is using those for\nsi_meminfo_node() without the validation of the value.  This can result in\nout of bounds memory access.  The issue can actually triggered using DAMON\nuser-space tool (damo), like below.\n\n    $ sudo ./damo start --damos_action stat \\\n    \t--damos_quota_goal node_mem_used_bp 50% -1 \\\n    \t--damos_quota_interval 1s\n    $ sudo dmesg\n    [...]\n    [   65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098\n\nFix this issue by adding the validation of the given node.  If an invalid\nnode id is given, it returns 0% for used memory ratio, and 100% for free\nmemory ratio."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0e1c773b501f33437d87b72c7d26080361e224b1","status":"affected","lessThan":"b09958e235f2b9cd3898b85a8529172afa80d212","versionType":"git"},{"version":"0e1c773b501f33437d87b72c7d26080361e224b1","status":"affected","lessThan":"bcad74078708f2330a45b55358ebc38f8f4b1127","versionType":"git"},{"version":"0e1c773b501f33437d87b72c7d26080361e224b1","status":"affected","lessThan":"40250b2dded0604a112be605f3828700d80ad7c2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/damon/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.27","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.4","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/damon/core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b09958e235f2b9cd3898b85a8529172afa80d212"},{"url":"https://git.kernel.org/stable/c/bcad74078708f2330a45b55358ebc38f8f4b1127"},{"url":"https://git.kernel.org/stable/c/40250b2dded0604a112be605f3828700d80ad7c2"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-06-14T17:48:26.041Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.27"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.0.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}