{"id":"CVE-2026-80602","title":"perf/x86/amd/lbr: Fix kernel address leakage","summary":"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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 5adfec05e804ce4bd3368b75df5e5b7b40ee960b","Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 5be478c1e08981ca91b34de310d7e2638171d9d8","Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 208ecca408b1707ad86ea247d3d3e09d3606fc13","Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 5ab0eba9c8819506bcb72348fd701f8a9006f95e","Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f","Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 2a892294b83f541115c94b0bb637f39bef187657","Linux 6.1"],"published":"2026-08-28","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:30:41.331Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80602","references":[{"url":"https://git.kernel.org/stable/c/5adfec05e804ce4bd3368b75df5e5b7b40ee960b"},{"url":"https://git.kernel.org/stable/c/5be478c1e08981ca91b34de310d7e2638171d9d8"},{"url":"https://git.kernel.org/stable/c/208ecca408b1707ad86ea247d3d3e09d3606fc13"},{"url":"https://git.kernel.org/stable/c/5ab0eba9c8819506bcb72348fd701f8a9006f95e"},{"url":"https://git.kernel.org/stable/c/fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f"},{"url":"https://git.kernel.org/stable/c/2a892294b83f541115c94b0bb637f39bef187657"}],"tags":["cve.org"],"epss":0.00215,"epssPercentile":0.11907,"ingestedAt":"2026-11-05T15:02:32.596Z","slug":"CVE-2026-80602","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 5adfec05e804ce4bd3368b75df5e5b7b40ee960b`\n- `Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 5be478c1e08981ca91b34de310d7e2638171d9d8`\n- `Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 208ecca408b1707ad86ea247d3d3e09d3606fc13`\n- `Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 5ab0eba9c8819506bcb72348fd701f8a9006f95e`\n- `Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f`\n- `Linux >= f4f925dae7419fc7a10af539c073871927ce3a24 < 2a892294b83f541115c94b0bb637f39bef187657`\n- `Linux 6.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}