FKIE_CVE-2026-72237

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-19 17:21
Severity
Summary
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/046f6244da9b68e463a849b21446b9424e531491
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2e706be56f418718bb3ae66c0aa94f9b61150e6d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/47915e855fb38b42133e31ba917d99565f862154
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/90843d00dbc61220b66408ea0d8775cae9e51f70
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ac44b4a3d6137489f8fa2e794b12e849c6b22eaa
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/events/amd/brs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1",
              "status": "affected",
              "version": "8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08",
              "versionType": "git"
            },
            {
              "lessThan": "ac44b4a3d6137489f8fa2e794b12e849c6b22eaa",
              "status": "affected",
              "version": "8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08",
              "versionType": "git"
            },
            {
              "lessThan": "90843d00dbc61220b66408ea0d8775cae9e51f70",
              "status": "affected",
              "version": "8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08",
              "versionType": "git"
            },
            {
              "lessThan": "046f6244da9b68e463a849b21446b9424e531491",
              "status": "affected",
              "version": "8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08",
              "versionType": "git"
            },
            {
              "lessThan": "2e706be56f418718bb3ae66c0aa94f9b61150e6d",
              "status": "affected",
              "version": "8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08",
              "versionType": "git"
            },
            {
              "lessThan": "47915e855fb38b42133e31ba917d99565f862154",
              "status": "affected",
              "version": "8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/events/amd/brs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/amd/brs: 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_BRS (Zen 3 only), perf can still report entries\nsuch as SYSRET/interrupt returns for which the branch-from addresses\nare in the kernel.\n\nE.g.\n\n  $ perf record -j any,u -c 4000 -e branch-brs -o - -- \\\n        perf bench syscall basic --loop 1000 | \\\n        perf script -i - -F brstack|tr \u0027 \u0027 \u0027\\n\u0027| \\\n        grep -E \u00270x[89a-f][0-9a-f]{15}\u0027\n\n  ...\n  0xffffffff810001c4/0x72e2e32955eb/-/-/-/0//-\n  0xffffffff810001c4/0x72e2d94a9821/-/-/-/0//-\n  0xffffffff810001c4/0x72e2d94ffa1b/-/-/-/0//-\n  ...\n\nBRS provides no hardware branch filtering, so privilege level\nfiltering is performed entirely in software. However, amd_brs_match_plm()\nonly validates the branch-to address against the requested privilege\nlevels. For branches from the kernel to user space, the branch-from\naddress is left unchecked and is leaked. Extend the software filter to\nalso validate the branch-from address, so that any branch record whose\nbranch-from address is in the kernel is dropped when\nPERF_SAMPLE_BRANCH_USER is requested."
    }
  ],
  "id": "CVE-2026-72237",
  "lastModified": "2026-08-19T17:21:00.693",
  "metrics": {},
  "published": "2026-08-15T06:21:50.733",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/046f6244da9b68e463a849b21446b9424e531491"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2e706be56f418718bb3ae66c0aa94f9b61150e6d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/47915e855fb38b42133e31ba917d99565f862154"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/90843d00dbc61220b66408ea0d8775cae9e51f70"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ac44b4a3d6137489f8fa2e794b12e849c6b22eaa"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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