{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43331", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.002Z", "datePublished": "2026-05-08T13:31:18.787Z", "dateUpdated": "2026-05-08T13:31:18.787Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-08T13:31:18.787Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/kexec: Disable KCOV instrumentation after load_segments()\n\nThe load_segments() function changes segment registers, invalidating GS base\n(which KCOV relies on for per-cpu data). When CONFIG_KCOV is enabled, any\nsubsequent instrumented C code call (e.g. native_gdt_invalidate()) begins\ncrashing the kernel in an endless loop.\n\nTo reproduce the problem, it's sufficient to do kexec on a KCOV-instrumented\nkernel:\n\n $ kexec -l /boot/otherKernel\n $ kexec -e\n\nThe real-world context for this problem is enabling crash dump collection in\nsyzkaller. For this, the tool loads a panic kernel before fuzzing and then\ncalls makedumpfile after the panic. This workflow requires both CONFIG_KEXEC\nand CONFIG_KCOV to be enabled simultaneously.\n\nAdding safeguards directly to the KCOV fast-path (__sanitizer_cov_trace_pc())\nis also undesirable as it would introduce an extra performance overhead.\n\nDisabling instrumentation for the individual functions would be too fragile,\nso disable KCOV instrumentation for the entire machine_kexec_64.c and\nphysaddr.c. If coverage-guided fuzzing ever needs these components in the\nfuture, other approaches should be considered.\n\nThe problem is not relevant for 32 bit kernels as CONFIG_KCOV is not supported\nthere.\n\n [ bp: Space out comment for better readability. ]"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kernel/Makefile", "arch/x86/mm/Makefile"], "versions": [{"version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "1e3e98596c2769721ade0418434852fb3af4849a", "status": "affected", "versionType": "git"}, {"version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "de05c66fab8847237a9ca216934e56d3ee837f08", "status": "affected", "versionType": "git"}, {"version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "917e3ad3321e75ca0223d5ccf26ceda116aa51e1", "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/kernel/Makefile", "arch/x86/mm/Makefile"], "versions": [{"version": "6.6", "status": "affected"}, {"version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.22", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.12", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "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": "6.6", "versionEndExcluding": "6.18.22"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.19.12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1e3e98596c2769721ade0418434852fb3af4849a"}, {"url": "https://git.kernel.org/stable/c/de05c66fab8847237a9ca216934e56d3ee837f08"}, {"url": "https://git.kernel.org/stable/c/917e3ad3321e75ca0223d5ccf26ceda116aa51e1"}], "title": "x86/kexec: Disable KCOV instrumentation after load_segments()", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/kexec: Disable KCOV instrumentation after load_segments()\n\nThe load_segments() function changes segment registers, invalidating GS base\n(which KCOV relies on for per-cpu data). When CONFIG_KCOV is enabled, any\nsubsequent instrumented C code call (e.g. native_gdt_invalidate()) begins\ncrashing the kernel in an endless loop.\n\nTo reproduce the problem, it's sufficient to do kexec on a KCOV-instrumented\nkernel:\n\n $ kexec -l /boot/otherKernel\n $ kexec -e\n\nThe real-world context for this problem is enabling crash dump collection in\nsyzkaller. For this, the tool loads a panic kernel before fuzzing and then\ncalls makedumpfile after the panic. This workflow requires both CONFIG_KEXEC\nand CONFIG_KCOV to be enabled simultaneously.\n\nAdding safeguards directly to the KCOV fast-path (__sanitizer_cov_trace_pc())\nis also undesirable as it would introduce an extra performance overhead.\n\nDisabling instrumentation for the individual functions would be too fragile,\nso disable KCOV instrumentation for the entire machine_kexec_64.c and\nphysaddr.c. If coverage-guided fuzzing ever needs these components in the\nfuture, other approaches should be considered.\n\nThe problem is not relevant for 32 bit kernels as CONFIG_KCOV is not supported\nthere.\n\n [ bp: Space out comment for better readability. ]"}], "id": "CVE-2026-43331", "lastModified": "2026-05-08T14:16:42.763", "metrics": {}, "published": "2026-05-08T14:16:42.763", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1e3e98596c2769721ade0418434852fb3af4849a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/917e3ad3321e75ca0223d5ccf26ceda116aa51e1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/de05c66fab8847237a9ca216934e56d3ee837f08"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}