perf/x86/amd/lbr: Fix kernel address leakage
Summary
| CVE | CVE-2026-80602 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-08-28 08:16:44 UTC |
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| Updated | 2026-08-28 08:16:44 UTC |
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| 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. |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| 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 6.6.145 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/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.