perf/x86/amd/lbr: Fix kernel address leakage
Summary
| CVE | CVE-2026-80602 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-28 08:16:44 UTC |
| Updated | 2026-10-30 13:20:07 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: perf/x86/amd/lbr: Fix kernel address leakage A user-only branch stack can contain branches that originate from the kernel. As a result, kernel addresses are exposed to user space even when PERF_SAMPLE_BRANCH_USER is requested. On AMD processors supporting X86_FEATURE_AMD_LBR_V2, perf can still report SYSRET/ERET entries for which the branch-from addresses are in the kernel. E.g. $ perf record -e cycles -o - -j any,save_type,u -- \ perf bench syscall basic --loop 1000 | \ perf script -i - -F brstack|tr ' ' '\n'| \ grep -E '0x[89a-f][0-9a-f]{15}' ... 0xffffffff81001268/0x717a90a38f1a/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a39157/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a2c628/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a41b60/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a90a260db/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a8bef1c30/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH 0xffffffff81001268/0x717a8e4d3c90/M/-/-/0/ERET/NON_SPEC_CORRECT_PATH ... The reason is that the hardware filter only considers the privilege level applicable to the branch target. Extend software filtering to also validate the branch-from addresses against br_sel, so that any branch record whose branch-from address is in the kernel is dropped when PERF_SAMPLE_BRANCH_USER is requested. |
Risk And Classification
EPSS: 0.001680000 probability, percentile 0.062780000 (date 2026-08-30)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected f4f925dae7419fc7a10af539c073871927ce3a24 5adfec05e804ce4bd3368b75df5e5b7b40ee960b git | Not specified |
| CNA | Linux | Linux | affected f4f925dae7419fc7a10af539c073871927ce3a24 5be478c1e08981ca91b34de310d7e2638171d9d8 git | Not specified |
| CNA | Linux | Linux | affected f4f925dae7419fc7a10af539c073871927ce3a24 208ecca408b1707ad86ea247d3d3e09d3606fc13 git | Not specified |
| CNA | Linux | Linux | affected f4f925dae7419fc7a10af539c073871927ce3a24 5ab0eba9c8819506bcb72348fd701f8a9006f95e git | Not specified |
| CNA | Linux | Linux | affected f4f925dae7419fc7a10af539c073871927ce3a24 fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f git | Not specified |
| CNA | Linux | Linux | affected f4f925dae7419fc7a10af539c073871927ce3a24 2a892294b83f541115c94b0bb637f39bef187657 git | Not specified |
| CNA | Linux | Linux | affected 6.1 | Not specified |
| CNA | Linux | Linux | unaffected 6.1 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.191 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.145 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.97 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.40 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.5 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/5be478c1e08981ca91b34de310d7e2638171d9d8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5ab0eba9c8819506bcb72348fd701f8a9006f95e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/208ecca408b1707ad86ea247d3d3e09d3606fc13 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/fb3b76b5ad2ebad63dd76f8b65b624eaf638b73f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5adfec05e804ce4bd3368b75df5e5b7b40ee960b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/2a892294b83f541115c94b0bb637f39bef187657 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.