{"id":"CVE-2026-72237","state":"PUBLISHED","title":"perf/x86/amd/brs: Fix kernel address leakage","description":"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 ' ' '\\n'| \\\n        grep -E '0x[89a-f][0-9a-f]{15}'\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.","publishedAt":"2026-08-15T05:54:26.685Z","updatedAt":"2026-08-19T16:36:31.271Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"ac44b4a3d6137489f8fa2e794b12e849c6b22eaa","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"90843d00dbc61220b66408ea0d8775cae9e51f70","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"046f6244da9b68e463a849b21446b9424e531491","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"2e706be56f418718bb3ae66c0aa94f9b61150e6d","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"47915e855fb38b42133e31ba917d99565f862154","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/events/amd/brs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/events/amd/brs.c"]}],"references":["https://git.kernel.org/stable/c/4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1","https://git.kernel.org/stable/c/ac44b4a3d6137489f8fa2e794b12e849c6b22eaa","https://git.kernel.org/stable/c/90843d00dbc61220b66408ea0d8775cae9e51f70","https://git.kernel.org/stable/c/046f6244da9b68e463a849b21446b9424e531491","https://git.kernel.org/stable/c/2e706be56f418718bb3ae66c0aa94f9b61150e6d","https://git.kernel.org/stable/c/47915e855fb38b42133e31ba917d99565f862154"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72237.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72237","state":"PUBLISHED","datePublished":"2026-08-15T05:54:26.685Z","dateUpdated":"2026-08-19T16:36:31.271Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.914Z"},"containers":{"cna":{"title":"perf/x86/amd/brs: Fix kernel address leakage","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 ' ' '\\n'| \\\n        grep -E '0x[89a-f][0-9a-f]{15}'\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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"ac44b4a3d6137489f8fa2e794b12e849c6b22eaa","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"90843d00dbc61220b66408ea0d8775cae9e51f70","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"046f6244da9b68e463a849b21446b9424e531491","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"2e706be56f418718bb3ae66c0aa94f9b61150e6d","versionType":"git"},{"version":"8910075d61a37e5b0d82e6c83ed9a0a31fe9ea08","status":"affected","lessThan":"47915e855fb38b42133e31ba917d99565f862154","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/events/amd/brs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/events/amd/brs.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4f949bc3913a6e3ce3b8574ac6ed1da8ec7a5ad1"},{"url":"https://git.kernel.org/stable/c/ac44b4a3d6137489f8fa2e794b12e849c6b22eaa"},{"url":"https://git.kernel.org/stable/c/90843d00dbc61220b66408ea0d8775cae9e51f70"},{"url":"https://git.kernel.org/stable/c/046f6244da9b68e463a849b21446b9424e531491"},{"url":"https://git.kernel.org/stable/c/2e706be56f418718bb3ae66c0aa94f9b61150e6d"},{"url":"https://git.kernel.org/stable/c/47915e855fb38b42133e31ba917d99565f862154"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:36:31.271Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}