{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2025-37936", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.971Z", "datePublished": "2025-05-20T15:22:00.557Z", "dateUpdated": "2025-05-26T05:24:05.383Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-05-26T05:24:05.383Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value.\n\nWhen generating the MSR_IA32_PEBS_ENABLE value that will be loaded on\nVM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS_ENABLE\nvalue. Consulting only the host kernel's host vs. guest masks results in\nrunning the guest with PEBS enabled even when the guest doesn't want to use\nPEBS. Because KVM uses perf events to proxy the guest virtual PMU, simply\nlooking at exclude_host can't differentiate between events created by host\nuserspace, and events created by KVM on behalf of the guest.\n\nRunning the guest with PEBS unexpectedly enabled typically manifests as\ncrashes due to a near-infinite stream of #PFs. E.g. if the guest hasn't\nwritten MSR_IA32_DS_AREA, the CPU will hit page faults on address '0' when\ntrying to record PEBS events.\n\nThe issue is most easily reproduced by running `perf kvm top` from before\ncommit 7b100989b4f6 (\"perf evlist: Remove __evlist__add_default\") (after\nwhich, `perf kvm top` effectively stopped using PEBS).\tThe userspace side\nof perf creates a guest-only PEBS event, which intel_guest_get_msrs()\nmisconstrues a guest-*owned* PEBS event.\n\nArguably, this is a userspace bug, as enabling PEBS on guest-only events\nsimply cannot work, and userspace can kill VMs in many other ways (there\nis no danger to the host). However, even if this is considered to be bad\nuserspace behavior, there's zero downside to perf/KVM restricting PEBS to\nguest-owned events.\n\nNote, commit 854250329c02 (\"KVM: x86/pmu: Disable guest PEBS temporarily\nin two rare situations\") fixed the case where host userspace is profiling\nKVM *and* userspace, but missed the case where userspace is profiling only\nKVM."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/events/intel/core.c"], "versions": [{"version": "c59a1f106f5cd4843c097069ff1bb2ad72103a67", "lessThan": "160153cf9e4aa875ad086cc094ce34aac8e13d63", "status": "affected", "versionType": "git"}, {"version": "c59a1f106f5cd4843c097069ff1bb2ad72103a67", "lessThan": "34b6fa11431aef71045ae5a00d90a7d630597eda", "status": "affected", "versionType": "git"}, {"version": "c59a1f106f5cd4843c097069ff1bb2ad72103a67", "lessThan": "44ee0afc9d1e7a7c1932698de01362ed80cfc4b5", "status": "affected", "versionType": "git"}, {"version": "c59a1f106f5cd4843c097069ff1bb2ad72103a67", "lessThan": "86aa62895fc2fb7ab09d7ca40fae8ad09841f66b", "status": "affected", "versionType": "git"}, {"version": "c59a1f106f5cd4843c097069ff1bb2ad72103a67", "lessThan": "58f6217e5d0132a9f14e401e62796916aa055c1b", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/events/intel/core.c"], "versions": [{"version": "6.0", "status": "affected"}, {"version": "0", "lessThan": "6.0", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.138", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.90", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.28", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.14.6", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.15", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.1.138"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.6.90"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.12.28"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.14.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.15"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/160153cf9e4aa875ad086cc094ce34aac8e13d63"}, {"url": "https://git.kernel.org/stable/c/34b6fa11431aef71045ae5a00d90a7d630597eda"}, {"url": "https://git.kernel.org/stable/c/44ee0afc9d1e7a7c1932698de01362ed80cfc4b5"}, {"url": "https://git.kernel.org/stable/c/86aa62895fc2fb7ab09d7ca40fae8ad09841f66b"}, {"url": "https://git.kernel.org/stable/c/58f6217e5d0132a9f14e401e62796916aa055c1b"}], "title": "perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value.", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value.\n\nWhen generating the MSR_IA32_PEBS_ENABLE value that will be loaded on\nVM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS_ENABLE\nvalue. Consulting only the host kernel's host vs. guest masks results in\nrunning the guest with PEBS enabled even when the guest doesn't want to use\nPEBS. Because KVM uses perf events to proxy the guest virtual PMU, simply\nlooking at exclude_host can't differentiate between events created by host\nuserspace, and events created by KVM on behalf of the guest.\n\nRunning the guest with PEBS unexpectedly enabled typically manifests as\ncrashes due to a near-infinite stream of #PFs. E.g. if the guest hasn't\nwritten MSR_IA32_DS_AREA, the CPU will hit page faults on address '0' when\ntrying to record PEBS events.\n\nThe issue is most easily reproduced by running `perf kvm top` from before\ncommit 7b100989b4f6 (\"perf evlist: Remove __evlist__add_default\") (after\nwhich, `perf kvm top` effectively stopped using PEBS).\tThe userspace side\nof perf creates a guest-only PEBS event, which intel_guest_get_msrs()\nmisconstrues a guest-*owned* PEBS event.\n\nArguably, this is a userspace bug, as enabling PEBS on guest-only events\nsimply cannot work, and userspace can kill VMs in many other ways (there\nis no danger to the host). However, even if this is considered to be bad\nuserspace behavior, there's zero downside to perf/KVM restricting PEBS to\nguest-owned events.\n\nNote, commit 854250329c02 (\"KVM: x86/pmu: Disable guest PEBS temporarily\nin two rare situations\") fixed the case where host userspace is profiling\nKVM *and* userspace, but missed the case where userspace is profiling only\nKVM."}], "id": "CVE-2025-37936", "lastModified": "2025-05-21T20:25:16.407", "metrics": {}, "published": "2025-05-20T16:15:30.443", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/160153cf9e4aa875ad086cc094ce34aac8e13d63"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/34b6fa11431aef71045ae5a00d90a7d630597eda"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/44ee0afc9d1e7a7c1932698de01362ed80cfc4b5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/58f6217e5d0132a9f14e401e62796916aa055c1b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/86aa62895fc2fb7ab09d7ca40fae8ad09841f66b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value.", "id": "2367541", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2367541"}, "csaw": false, "cvss3": {"cvss3_base_score": "3.3", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nperf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value.\nWhen generating the MSR_IA32_PEBS_ENABLE value that will be loaded on\nVM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS_ENABLE\nvalue. Consulting only the host kernel's host vs. guest masks results in\nrunning the guest with PEBS enabled even when the guest doesn't want to use\nPEBS. Because KVM uses perf events to proxy the guest virtual PMU, simply\nlooking at exclude_host can't differentiate between events created by host\nuserspace, and events created by KVM on behalf of the guest.\nRunning the guest with PEBS unexpectedly enabled typically manifests as\ncrashes due to a near-infinite stream of #PFs. E.g. if the guest hasn't\nwritten MSR_IA32_DS_AREA, the CPU will hit page faults on address '0' when\ntrying to record PEBS events.\nThe issue is most easily reproduced by running `perf kvm top` from before\ncommit 7b100989b4f6 (\"perf evlist: Remove __evlist__add_default\") (after\nwhich, `perf kvm top` effectively stopped using PEBS).The userspace side\nof perf creates a guest-only PEBS event, which intel_guest_get_msrs()\nmisconstrues a guest-*owned* PEBS event.\nArguably, this is a userspace bug, as enabling PEBS on guest-only events\nsimply cannot work, and userspace can kill VMs in many other ways (there\nis no danger to the host). However, even if this is considered to be bad\nuserspace behavior, there's zero downside to perf/KVM restricting PEBS to\nguest-owned events.\nNote, commit 854250329c02 (\"KVM: x86/pmu: Disable guest PEBS temporarily\nin two rare situations\") fixed the case where host userspace is profiling\nKVM *and* userspace, but missed the case where userspace is profiling only\nKVM."], "name": "CVE-2025-37936", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-05-20T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-37936\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-37936\nhttps://lore.kernel.org/linux-cve-announce/2025052008-CVE-2025-37936-a210@gregkh/T"], "statement": "This patch prevents unintended activation of PEBS for KVM guests that have not explicitly enabled it. Failing to do so could cause infinite #PF exceptions and VM crashes due to invalid memory accesses (e.g., DS_AREA == 0). This is a correctness and stability issue critical for safe VM operation.", "threat_severity": "Low"}