{"id":"CVE-2026-97960","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Prevent drain_pebs() reentry\n\nThe PEBS buffer is shared by all events on a CPU, so drain_pebs() must\nnot be reentered","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Prevent drain_pebs() reentry\n\nThe PEBS buffer is shared by all events on a CPU, so drain_pebs() must\nnot be reentered. If so, one instance may observe s…","severity":"medium","vendor":"Linux","product":"Linux","affected":["Linux >= b752ea0c28e3f7f0aaaad6abf84f735eebc37a60 < a5fe19dd8b3ed5fad6e5e0f0c58c7245043ee4af","Linux >= b752ea0c28e3f7f0aaaad6abf84f735eebc37a60 < c55599c0ec2aa020e41a0599c3044c56d8a2e7d9","Linux >= b752ea0c28e3f7f0aaaad6abf84f735eebc37a60 < a56c03a397e2cd0c4cf8da96dcd6214f7d0e7d8c","Linux a9165207b2b07415eeb01b3ac8bb84976ec96984","Linux >= 6.3.7 < 6.4","Linux 6.4"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:23.720","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97960","references":[{"url":"https://git.kernel.org/stable/c/a56c03a397e2cd0c4cf8da96dcd6214f7d0e7d8c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a5fe19dd8b3ed5fad6e5e0f0c58c7245043ee4af","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c55599c0ec2aa020e41a0599c3044c56d8a2e7d9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97960.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-97960"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541044"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97960"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97960"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97960.mbox"},{"url":"https://git.kernel.org/stable/c/9882068ed242fcd4743f53027e8c790e88dcafff"},{"url":"https://git.kernel.org/stable/c/999e482fdf89400cc1ae937680fc05096b4c915b"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-09-25T11:06:38.875Z","epss":0.00168,"epssPercentile":0.06161,"cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-663"],"slug":"CVE-2026-97960","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Prevent drain_pebs() reentry\n\nThe PEBS buffer is shared by all events on a CPU, so drain_pebs() must\nnot be reentered. If so, one instance may observe stale buffer state and\npotentially access out-of-bound memory.\n\nMost invocations happen in NMI context, which naturally prevents reentry.\nHowever, drain_pebs() is also reachable from process context via\nintel_pmu_drain_pebs_buffer().\n\nIn those paths, the PMU is often already disabled, but not guaranteed.\nFor example, __intel_pmu_pebs_disable() only disables the target counter,\nso other active counters can still raise a PMI and interrupt an in-flight\ndrain_pebs(). Here is an example,\n\n__perf_addr_filters_adjust()\n  perf_event_stop()\n    __perf_event_stop()\n      x86_pmu_stop() (event->pmu->stop)\n        intel_pmu_disable_event()\n          intel_pmu_pebs_disable()\n            __intel_pmu_pebs_disable()\n              intel_pmu_drain_large_pebs()\n                intel_pmu_drain_pebs_buffer()\n\nIntroduce __intel_pmu_quiesce() and __intel_pmu_resume() helpers and\nuse them in intel_pmu_drain_large_pebs() to disable the full PMU\naround the intel_pmu_drain_pebs_buffer() call, preventing reentry.\n\nAlso add a warning in intel_pmu_drain_pebs_buffer() when the full PMU is\nnot disabled.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97960.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":213395,"id":"CVE-2026-97960","ts":1790754704570,"field":"cvss","old":null,"new":"5.5"},{"seq":213394,"id":"CVE-2026-97960","ts":1790754704570,"field":"severity","old":"none","new":"medium"}]}