perf/x86/amd/brs: Fix kernel address leakage
Summary
| CVE | CVE-2026-72237 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-15 06:21:50 UTC |
| Updated | 2026-08-19 17:21:00 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: perf/x86/amd/brs: 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_BRS (Zen 3 only), perf can still report entries such as SYSRET/interrupt returns for which the branch-from addresses are in the kernel. E.g. $ perf record -j any,u -c 4000 -e branch-brs -o - -- \ perf bench syscall basic --loop 1000 | \ perf script -i - -F brstack|tr ' ' '\n'| \ grep -E '0x[89a-f][0-9a-f]{15}' ... 0xffffffff810001c4/0x72e2e32955eb/-/-/-/0//- 0xffffffff810001c4/0x72e2d94a9821/-/-/-/0//- 0xffffffff810001c4/0x72e2d94ffa1b/-/-/-/0//- ... BRS provides no hardware branch filtering, so privilege level filtering is performed entirely in software. However, amd_brs_match_plm() only validates the branch-to address against the requested privilege levels. For branches from the kernel to user space, the branch-from address is left unchecked and is leaked. Extend the software filter to also validate the branch-from address, 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: 0.002000000 probability, percentile 0.102290000 (date 2026-08-19)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08 4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1 git | Not specified |
| CNA | Linux | Linux | affected 8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08 ac44b4a3d6137489f8fa2e794b12e849c6b22eaa git | Not specified |
| CNA | Linux | Linux | affected 8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08 90843d00dbc61220b66408ea0d8775cae9e51f70 git | Not specified |
| CNA | Linux | Linux | affected 8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08 046f6244da9b68e463a849b21446b9424e531491 git | Not specified |
| CNA | Linux | Linux | affected 8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08 2e706be56f418718bb3ae66c0aa94f9b61150e6d git | Not specified |
| CNA | Linux | Linux | affected 8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08 47915e855fb38b42133e31ba917d99565f862154 git | Not specified |
| CNA | Linux | Linux | affected 5.19 | Not specified |
| CNA | Linux | Linux | unaffected 5.19 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.183 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/2e706be56f418718bb3ae66c0aa94f9b61150e6d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/47915e855fb38b42133e31ba917d99565f862154 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/90843d00dbc61220b66408ea0d8775cae9e51f70 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ac44b4a3d6137489f8fa2e794b12e849c6b22eaa | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/046f6244da9b68e463a849b21446b9424e531491 | 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.