{"id":"CVE-2026-80602","summary":"perf/x86/amd/lbr: Fix kernel address leakage","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/amd/lbr: Fix kernel address leakage\n\nA user-only branch stack can contain branches that originate from\nthe kernel. As a result, kernel addresses are exposed to user space\neven when PERF_SAMPLE_BRANCH_USER is requested. On AMD processors\nsupporting X86_FEATURE_AMD_LBR_V2, perf can still report SYSRET/ERET\nentries for which the branch-from addresses are in the kernel.\n\nE.g.\n\n  $ perf record -e cycles -o - -j any,save_type,u -- \\\n        perf bench syscall basic --loop 1000 | \\\n        perf script -i - -F brstack|tr ' ' '\\n'| \\\n        grep -E '0x[89a-f][0-9a-f]{15}'\n\n  ...\n  0xffffffff81001268/0x717a90a38f1a/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a39157/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a2c628/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a41b60/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a8bef1c30/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  0xffffffff81001268/0x717a8e4d3c90/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH\n  ...\n\nThe reason is that the hardware filter only considers the privilege\nlevel applicable to the branch target. Extend software filtering to\nalso validate the branch-from addresses against br_sel, so that any\nbranch record whose branch-from address is in the kernel is dropped\nwhen PERF_SAMPLE_BRANCH_USER is requested.","modified":"2026-08-30T03:48:22.922151234Z","published":"2026-08-28T06:48:28.553Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80602.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/208ecca408b1707ad86ea247d3d3e09d3606fc13"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2a892294b83f541115c94b0bb637f39bef187657"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5ab0eba9c8819506bcb72348fd701f8a9006f95e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5be478c1e08981ca91b34de310d7e2638171d9d8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80602.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80602"},{"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":"f4f925dae7419fc7a10af539c073871927ce3a24"},{"fixed":"5be478c1e08981ca91b34de310d7e2638171d9d8"},{"fixed":"208ecca408b1707ad86ea247d3d3e09d3606fc13"},{"fixed":"5ab0eba9c8819506bcb72348fd701f8a9006f95e"},{"fixed":"fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f"},{"fixed":"2a892294b83f541115c94b0bb637f39bef187657"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80602.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.1.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80602.json"}}],"schema_version":"1.9.0"}