cve-2025-40300
Vulnerability from cvelistv5
Published
2025-09-11 16:49
Modified
2025-09-15 06:47
Severity ?
EPSS score ?
Summary
x86/vmscape: Add conditional IBPB mitigation
References
{ "containers": { "cna": { "affected": [ { "defaultStatus": "unaffected", "product": "Linux", "programFiles": [ "arch/x86/include/asm/cpufeatures.h", "arch/x86/include/asm/entry-common.h", "arch/x86/include/asm/nospec-branch.h", "arch/x86/kernel/cpu/bugs.c", "arch/x86/kvm/x86.c" ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [ { "lessThan": "ac60717f9a8d21c58617d0b34274babf24135835", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "c08192b5d6730a914dee6175bc71092ee6a65f14", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "d5490dfa35427a2967e00a4c7a1b95fdbc8ede34", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "2f4f2f8f860cb4c3336a7435ebe8dcfded0c9c6e", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "15006289e5c38b2a830e1fba221977a27598176c", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "893387c18612bb452336a5881da0d015a7e8f4a2", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "f866eef8d1c65504d30923c3f14082ad294d0e6d", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "34e5667041050711a947e260fc9ebebe08bddee5", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "d7ddc93392e4a7ffcccc86edf6ef3e64c778db52", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "459274c77b37ac63b78c928b4b4e748d1f9d05c8", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "510603f504796c3535f67f55fb0b124a303b44c8", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "9c23a90648e831d611152ac08dbcd1283d405e7f", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" }, { "lessThan": "2f8f173413f1cbf52660d04df92d0069c4306d25", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git" } ] }, { "defaultStatus": "affected", "product": "Linux", "programFiles": [ "arch/x86/include/asm/cpufeatures.h", "arch/x86/include/asm/entry-common.h", "arch/x86/include/asm/nospec-branch.h", "arch/x86/kernel/cpu/bugs.c", "arch/x86/kvm/x86.c" ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [ { "lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.244", "versionType": "semver" }, { "lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.193", "versionType": "semver" }, { "lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.152", "versionType": "semver" }, { "lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.106", "versionType": "semver" }, { "lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.47", "versionType": "semver" }, { "lessThanOrEqual": "6.16.*", "status": "unaffected", "version": "6.16.7", "versionType": "semver" }, { "lessThanOrEqual": "*", "status": "unaffected", "version": "6.17-rc6", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.10.244", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.10.244", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.15.193", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.15.193", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.1.152", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.1.152", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.6.106", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.6.106", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.12.47", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.12.47", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.16.7", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.16.7", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.17-rc6", "vulnerable": true } ], "negate": false, "operator": "OR" } ] } ], "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/vmscape: Add conditional IBPB mitigation\n\nVMSCAPE is a vulnerability that exploits insufficient branch predictor\nisolation between a guest and a userspace hypervisor (like QEMU). Existing\nmitigations already protect kernel/KVM from a malicious guest. Userspace\ncan additionally be protected by flushing the branch predictors after a\nVMexit.\n\nSince it is the userspace that consumes the poisoned branch predictors,\nconditionally issue an IBPB after a VMexit and before returning to\nuserspace. Workloads that frequently switch between hypervisor and\nuserspace will incur the most overhead from the new IBPB.\n\nThis new IBPB is not integrated with the existing IBPB sites. For\ninstance, a task can use the existing speculation control prctl() to\nget an IBPB at context switch time. With this implementation, the\nIBPB is doubled up: one at context switch and another before running\nuserspace.\n\nThe intent is to integrate and optimize these cases post-embargo.\n\n[ dhansen: elaborate on suboptimal IBPB solution ]" } ], "providerMetadata": { "dateUpdated": "2025-09-15T06:47:56.333Z", "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux" }, "references": [ { "url": "https://git.kernel.org/stable/c/ac60717f9a8d21c58617d0b34274babf24135835" }, { "url": "https://git.kernel.org/stable/c/c08192b5d6730a914dee6175bc71092ee6a65f14" }, { "url": "https://git.kernel.org/stable/c/d5490dfa35427a2967e00a4c7a1b95fdbc8ede34" }, { "url": "https://git.kernel.org/stable/c/2f4f2f8f860cb4c3336a7435ebe8dcfded0c9c6e" }, { "url": "https://git.kernel.org/stable/c/15006289e5c38b2a830e1fba221977a27598176c" }, { "url": "https://git.kernel.org/stable/c/893387c18612bb452336a5881da0d015a7e8f4a2" }, { "url": "https://git.kernel.org/stable/c/f866eef8d1c65504d30923c3f14082ad294d0e6d" }, { "url": "https://git.kernel.org/stable/c/34e5667041050711a947e260fc9ebebe08bddee5" }, { "url": "https://git.kernel.org/stable/c/d7ddc93392e4a7ffcccc86edf6ef3e64c778db52" }, { "url": "https://git.kernel.org/stable/c/459274c77b37ac63b78c928b4b4e748d1f9d05c8" }, { "url": "https://git.kernel.org/stable/c/510603f504796c3535f67f55fb0b124a303b44c8" }, { "url": "https://git.kernel.org/stable/c/9c23a90648e831d611152ac08dbcd1283d405e7f" }, { "url": "https://git.kernel.org/stable/c/2f8f173413f1cbf52660d04df92d0069c4306d25" } ], "title": "x86/vmscape: Add conditional IBPB mitigation", "x_generator": { "engine": "bippy-1.2.0" } } }, "cveMetadata": { "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "assignerShortName": "Linux", "cveId": "CVE-2025-40300", "datePublished": "2025-09-11T16:49:24.809Z", "dateReserved": "2025-04-16T07:20:57.185Z", "dateUpdated": "2025-09-15T06:47:56.333Z", "state": "PUBLISHED" }, "dataType": "CVE_RECORD", "dataVersion": "5.1", "meta": { "nvd": "{\"cve\":{\"id\":\"CVE-2025-40300\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-09-11T17:15:45.680\",\"lastModified\":\"2025-09-15T15:22:38.297\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nx86/vmscape: Add conditional IBPB mitigation\\n\\nVMSCAPE is a vulnerability that exploits insufficient branch predictor\\nisolation between a guest and a userspace hypervisor (like QEMU). Existing\\nmitigations already protect kernel/KVM from a malicious guest. Userspace\\ncan additionally be protected by flushing the branch predictors after a\\nVMexit.\\n\\nSince it is the userspace that consumes the poisoned branch predictors,\\nconditionally issue an IBPB after a VMexit and before returning to\\nuserspace. Workloads that frequently switch between hypervisor and\\nuserspace will incur the most overhead from the new IBPB.\\n\\nThis new IBPB is not integrated with the existing IBPB sites. For\\ninstance, a task can use the existing speculation control prctl() to\\nget an IBPB at context switch time. With this implementation, the\\nIBPB is doubled up: one at context switch and another before running\\nuserspace.\\n\\nThe intent is to integrate and optimize these cases post-embargo.\\n\\n[ dhansen: elaborate on suboptimal IBPB solution ]\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/15006289e5c38b2a830e1fba221977a27598176c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2f4f2f8f860cb4c3336a7435ebe8dcfded0c9c6e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2f8f173413f1cbf52660d04df92d0069c4306d25\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/34e5667041050711a947e260fc9ebebe08bddee5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/459274c77b37ac63b78c928b4b4e748d1f9d05c8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/510603f504796c3535f67f55fb0b124a303b44c8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/893387c18612bb452336a5881da0d015a7e8f4a2\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9c23a90648e831d611152ac08dbcd1283d405e7f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ac60717f9a8d21c58617d0b34274babf24135835\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c08192b5d6730a914dee6175bc71092ee6a65f14\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d5490dfa35427a2967e00a4c7a1b95fdbc8ede34\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d7ddc93392e4a7ffcccc86edf6ef3e64c778db52\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f866eef8d1c65504d30923c3f14082ad294d0e6d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}" } }
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- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
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- Patched: This vulnerability was successfully patched by the user reporting the sighting.
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