{"id":"CVE-2026-53370","summary":"perf/x86/intel: Improve validation and configuration of ACR masks","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Improve validation and configuration of ACR masks\n\nCurrently there are several issues on the user space ACR mask validation\nand configuration.\n- The validation for user space ACR mask (attr.config2) is incomplete,\n  e.g., the ACR mask could include the index which belongs to another\n  ACR events group, but it's not validated.\n- An early return on an invalid ACR mask caused all subsequent ACR groups\n  to be skipped.\n- The stale hardware ACR mask (hw.config1) is not cleared before setting\n  new hardware ACR mask.\n\nThe following changes address all of the above issues.\n- Figure out the event index group of an ACR group. Any bits in the\n  user-space mask not present in the index group are now dropped.\n- Instead of an early return on invalid bits, drop only the invalid\n  portions and continue iterating through all ACR events to ensure full\n  configuration.\n- Explicitly clear the stale hardware ACR mask for each event prior to\n  writing the new configuration.\n\nBesides, a non-leader event member of ACR group could be disabled in\ntheory. This could cause bit-shifting errors in the acr_mask of remaining\ngroup members. But since ACR sampling requires all events to be active,\nthis should not be a big concern in real use case. Add a \"FIXME\" comment\nto notice this risk.","modified":"2026-07-21T03:47:20.828982641Z","published":"2026-07-19T09:10:30.990Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53370.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5ad732a56be46aabf158c16aa0c095291727aaef"},{"type":"WEB","url":"https://git.kernel.org/stable/c/aab56b95bee3ff79176b13443cd9d7cfe9747df0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c05e01cef47d9b4969eae2dcf9467e2a555bcb4f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53370.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53370"},{"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":"ec980e4facef8110f6fce27e5b6344660117f01f"},{"fixed":"aab56b95bee3ff79176b13443cd9d7cfe9747df0"},{"fixed":"c05e01cef47d9b4969eae2dcf9467e2a555bcb4f"},{"fixed":"5ad732a56be46aabf158c16aa0c095291727aaef"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53370.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.30"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53370.json"}}],"schema_version":"1.7.5"}