{"id":"CVE-2026-64402","summary":"coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncoresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()\n\nWhen the SMB sink is used as a perf AUX sink, smb_update_buffer() calls\nsmb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring\nbuffer pages. It derives pg_idx = head \u003e\u003e PAGE_SHIFT from @head, which is\nhandle-\u003ehead, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages\nnormalization is only applied after the first loop iteration.\n\nThis leaves the initial page index underived from the buffer size, which\ncan result in an out-of-bounds write past dst_pages[] when head exceeds\nthe AUX buffer size.\n\nNormalize head modulo the AUX buffer size before deriving the page index\nand offset, mirroring tmc_etr_sync_perf_buffer().","modified":"2026-07-28T04:03:00.989387023Z","published":"2026-07-25T08:50:45.075Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64402.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64402.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64402"},{"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":"06f5c2926aaa0fba7f99678da6ef77cbbbda1441"},{"fixed":"38dbc8db8341ccdf8e1e1a067453d33ad751864b"},{"fixed":"4c5a0a946373da99a80398289b28845b5ae40cd1"},{"fixed":"661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb"},{"fixed":"daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f"},{"fixed":"98495b5a4d77dd22e106f462b76e1093a55b29a7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64402.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.3.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.96"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.39"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64402.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}