{"api_version":"1","generated_at":"2026-09-16T18:15:43+00:00","cve":"CVE-2026-89984","urls":{"html":"https://cve.report/CVE-2026-89984","api":"https://cve.report/api/cve/CVE-2026-89984.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89984","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89984"},"summary":{"title":"perf/x86/intel: Fix kernel address leakages in LBR stack","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Fix kernel address leakages in LBR stack\n\nBefore Arch LBR gained CPL filtering support, a user-only branch stack\ncould still contain kernel addresses. As a result, kernel branch records\nmay be exposed to user space even when PERF_SAMPLE_BRANCH_USER is\nrequested.\n\nFor example, on Intel Tiger Lake, the following command can still report\nSYSRET/ERET entries with kernel-space from addresses:\n\n$ ./perf record -e cycles:p -o - --branch-filter any,save_type,u -- \\\n \t./perf bench syscall basic --loop 1000 | \\\n\t./perf script -i - --fields brstack|tr ' ' '\\n'| \\\n\tgrep -E '0x[89a-f][0-9a-f]{15}'\n\n    Total time: 0.000 [sec]\n\n      0.219000 usecs/op\n     4,566,210 ops/sec\n[ perf record: Woken up 1 times to write data ]\n[ perf record: Captured and wrote 0.551 MB - ]\n0xffffffff93c001c8/0x7f12a2b1d647/P/-/-/16959/SYSRET/-\n0xffffffff93c001c8/0x7f12a2b1d5c2/P/-/-/17535/SYSRET/-\n0xffffffff93c01928/0x7f12a2861000/P/-/-/6719/ERET/-\n0xffffffff93c01928/0x7f12a297a000/P/-/-/8575/ERET/-\n\nThe problem is that intel_pmu_lbr_filter() does not fully validate the\nprivilege level of sampled entries. It filters some mismatches based on\nthe branch type and the to address, but it does not reject entries whose\nfrom address violates the requested branch privilege filter.\n\nFix this by extending software filtering to validate both from and to\naddresses against br_sel. Any LBR entry contains kernel address does not\nmatch the requested user filter is dropped. This prevents kernel\naddresses from appearing in user-only branch stacks.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:17:09","updated_at":"2026-09-16 11:17:09"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6ac26161db27f7fb9d9e89ae240dbe52795496cc","name":"https://git.kernel.org/stable/c/6ac26161db27f7fb9d9e89ae240dbe52795496cc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3c492c8eba02698ca893a9a13388d2adf6dfb839","name":"https://git.kernel.org/stable/c/3c492c8eba02698ca893a9a13388d2adf6dfb839","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/68c4b780b266a435261a1e029bede5ee3c2735cc","name":"https://git.kernel.org/stable/c/68c4b780b266a435261a1e029bede5ee3c2735cc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b589147f54adc62e4172e4acf079ad5fb7b3687f","name":"https://git.kernel.org/stable/c/b589147f54adc62e4172e4acf079ad5fb7b3687f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ca19a175e89b7de604fab736436cbab74030b47a","name":"https://git.kernel.org/stable/c/ca19a175e89b7de604fab736436cbab74030b47a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/be0628a101ac05b085aaa4f650d48bd3915e80fa","name":"https://git.kernel.org/stable/c/be0628a101ac05b085aaa4f650d48bd3915e80fa","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f3705db4e6378cc1b91a38ce0fe2f879055e23ca","name":"https://git.kernel.org/stable/c/f3705db4e6378cc1b91a38ce0fe2f879055e23ca","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e2b0575900ff72aa82748af96e7bd564ade5157a","name":"https://git.kernel.org/stable/c/e2b0575900ff72aa82748af96e7bd564ade5157a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89984","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89984","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 f3705db4e6378cc1b91a38ce0fe2f879055e23ca git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 b589147f54adc62e4172e4acf079ad5fb7b3687f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 be0628a101ac05b085aaa4f650d48bd3915e80fa git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 ca19a175e89b7de604fab736436cbab74030b47a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 6ac26161db27f7fb9d9e89ae240dbe52795496cc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 3c492c8eba02698ca893a9a13388d2adf6dfb839 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 68c4b780b266a435261a1e029bede5ee3c2735cc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47125db27e47e9d44c878bf8925aa057824bb0d5 e2b0575900ff72aa82748af96e7bd564ade5157a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.270 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.221 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.188 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.157 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.110 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.51 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.5 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/x86/events/intel/lbr.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f3705db4e6378cc1b91a38ce0fe2f879055e23ca","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"},{"lessThan":"b589147f54adc62e4172e4acf079ad5fb7b3687f","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"},{"lessThan":"be0628a101ac05b085aaa4f650d48bd3915e80fa","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"},{"lessThan":"ca19a175e89b7de604fab736436cbab74030b47a","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"},{"lessThan":"6ac26161db27f7fb9d9e89ae240dbe52795496cc","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"},{"lessThan":"3c492c8eba02698ca893a9a13388d2adf6dfb839","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"},{"lessThan":"68c4b780b266a435261a1e029bede5ee3c2735cc","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"},{"lessThan":"e2b0575900ff72aa82748af96e7bd564ade5157a","status":"affected","version":"47125db27e47e9d44c878bf8925aa057824bb0d5","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/x86/events/intel/lbr.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.9"},{"lessThan":"5.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.270","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.221","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.188","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.157","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.270","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.221","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.188","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.157","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.110","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.5","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"5.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Fix kernel address leakages in LBR stack\n\nBefore Arch LBR gained CPL filtering support, a user-only branch stack\ncould still contain kernel addresses. As a result, kernel branch records\nmay be exposed to user space even when PERF_SAMPLE_BRANCH_USER is\nrequested.\n\nFor example, on Intel Tiger Lake, the following command can still report\nSYSRET/ERET entries with kernel-space from addresses:\n\n$ ./perf record -e cycles:p -o - --branch-filter any,save_type,u -- \\\n \t./perf bench syscall basic --loop 1000 | \\\n\t./perf script -i - --fields brstack|tr ' ' '\\n'| \\\n\tgrep -E '0x[89a-f][0-9a-f]{15}'\n\n    Total time: 0.000 [sec]\n\n      0.219000 usecs/op\n     4,566,210 ops/sec\n[ perf record: Woken up 1 times to write data ]\n[ perf record: Captured and wrote 0.551 MB - ]\n0xffffffff93c001c8/0x7f12a2b1d647/P/-/-/16959/SYSRET/-\n0xffffffff93c001c8/0x7f12a2b1d5c2/P/-/-/17535/SYSRET/-\n0xffffffff93c01928/0x7f12a2861000/P/-/-/6719/ERET/-\n0xffffffff93c01928/0x7f12a297a000/P/-/-/8575/ERET/-\n\nThe problem is that intel_pmu_lbr_filter() does not fully validate the\nprivilege level of sampled entries. It filters some mismatches based on\nthe branch type and the to address, but it does not reject entries whose\nfrom address violates the requested branch privilege filter.\n\nFix this by extending software filtering to validate both from and to\naddresses against br_sel. Any LBR entry contains kernel address does not\nmatch the requested user filter is dropped. This prevents kernel\naddresses from appearing in user-only branch stacks."}],"providerMetadata":{"dateUpdated":"2026-09-16T10:33:00.162Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f3705db4e6378cc1b91a38ce0fe2f879055e23ca"},{"url":"https://git.kernel.org/stable/c/b589147f54adc62e4172e4acf079ad5fb7b3687f"},{"url":"https://git.kernel.org/stable/c/be0628a101ac05b085aaa4f650d48bd3915e80fa"},{"url":"https://git.kernel.org/stable/c/ca19a175e89b7de604fab736436cbab74030b47a"},{"url":"https://git.kernel.org/stable/c/6ac26161db27f7fb9d9e89ae240dbe52795496cc"},{"url":"https://git.kernel.org/stable/c/3c492c8eba02698ca893a9a13388d2adf6dfb839"},{"url":"https://git.kernel.org/stable/c/68c4b780b266a435261a1e029bede5ee3c2735cc"},{"url":"https://git.kernel.org/stable/c/e2b0575900ff72aa82748af96e7bd564ade5157a"}],"title":"perf/x86/intel: Fix kernel address leakages in LBR stack","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89984","datePublished":"2026-09-16T10:33:00.162Z","dateReserved":"2026-09-11T19:38:34.779Z","dateUpdated":"2026-09-16T10:33:00.162Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:17:09","lastModifiedDate":"2026-09-16 11:17:09","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89984","Ordinal":"1","Title":"perf/x86/intel: Fix kernel address leakages in LBR stack","CVE":"CVE-2026-89984","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89984","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Fix kernel address leakages in LBR stack\n\nBefore Arch LBR gained CPL filtering support, a user-only branch stack\ncould still contain kernel addresses. As a result, kernel branch records\nmay be exposed to user space even when PERF_SAMPLE_BRANCH_USER is\nrequested.\n\nFor example, on Intel Tiger Lake, the following command can still report\nSYSRET/ERET entries with kernel-space from addresses:\n\n$ ./perf record -e cycles:p -o - --branch-filter any,save_type,u -- \\\n \t./perf bench syscall basic --loop 1000 | \\\n\t./perf script -i - --fields brstack|tr ' ' '\\n'| \\\n\tgrep -E '0x[89a-f][0-9a-f]{15}'\n\n    Total time: 0.000 [sec]\n\n      0.219000 usecs/op\n     4,566,210 ops/sec\n[ perf record: Woken up 1 times to write data ]\n[ perf record: Captured and wrote 0.551 MB - ]\n0xffffffff93c001c8/0x7f12a2b1d647/P/-/-/16959/SYSRET/-\n0xffffffff93c001c8/0x7f12a2b1d5c2/P/-/-/17535/SYSRET/-\n0xffffffff93c01928/0x7f12a2861000/P/-/-/6719/ERET/-\n0xffffffff93c01928/0x7f12a297a000/P/-/-/8575/ERET/-\n\nThe problem is that intel_pmu_lbr_filter() does not fully validate the\nprivilege level of sampled entries. It filters some mismatches based on\nthe branch type and the to address, but it does not reject entries whose\nfrom address violates the requested branch privilege filter.\n\nFix this by extending software filtering to validate both from and to\naddresses against br_sel. Any LBR entry contains kernel address does not\nmatch the requested user filter is dropped. This prevents kernel\naddresses from appearing in user-only branch stacks.","Type":"Description","Title":"perf/x86/intel: Fix kernel address leakages in LBR stack"}]}}}