{"cve":"CVE-2026-46020","nvd":{"published":"2026-05-27T14:17:20.460","modified":"2026-06-17T10:52:54.690","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":7.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/40250b2dded0604a112be605f3828700d80ad7c2","https://git.kernel.org/stable/c/b09958e235f2b9cd3898b85a8529172afa80d212","https://git.kernel.org/stable/c/bcad74078708f2330a45b55358ebc38f8f4b1127"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:36:28.938604137+00:00"},"epss":{"cve":"CVE-2026-46020","score":0.00124,"percentile":0.02097,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}