{"id":"CVE-2026-46020","summary":"mm/damon/core: validate damos_quota_goal-\u003enid for node_mem_{used,free}_bp","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: validate damos_quota_goal-\u003enid for node_mem_{used,free}_bp\n\nPatch series \"mm/damon/core: validate damos_quota_goal-\u003enid\".\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-\u003enid 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.","modified":"2026-06-18T03:56:15.786365602Z","published":"2026-05-27T12:56:21.920Z","related":["openSUSE-SU-2026:10954-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46020.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/40250b2dded0604a112be605f3828700d80ad7c2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b09958e235f2b9cd3898b85a8529172afa80d212"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bcad74078708f2330a45b55358ebc38f8f4b1127"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46020.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46020"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0e1c773b501f33437d87b72c7d26080361e224b1"},{"fixed":"b09958e235f2b9cd3898b85a8529172afa80d212"},{"fixed":"bcad74078708f2330a45b55358ebc38f8f4b1127"},{"fixed":"40250b2dded0604a112be605f3828700d80ad7c2"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-46020.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.27"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-46020.json"}}],"schema_version":"1.7.5"}