CVE-2026-89981

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89981", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.779Z", "datePublished": "2026-09-16T10:32:58.056Z", "dateUpdated": "2026-10-19T08:55:55.850Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:55:55.850Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: Don't read GMID_EL1 when MTE is disabled\n\n__cpuinfo_store_cpu() gates the GMID_EL1 read on the raw\nID_AA64PFR1_EL1, so it reads the register even when the kernel has\ndisabled MTE (CONFIG_ARM64_MTE=n or arm64.nomte). KVM sets HCR_EL2.TID5\nin that case, and pKVM injects an UNDEF the host cannot handle:\n\n Internal error: Oops - Undefined instruction: 0000000002000000 [#1] SMP\n pc : __cpuinfo_store_cpu+0xf4/0x264\n Kernel panic - not syncing: Attempted to kill the idle task!\n\nOnly pKVM reaches it, and only after a CPU is offlined and brought back\nonline: its CPU_ON relay sets the host HCR before the CPU enters EL1,\nwhile plain nVHE sets it at CPUHP_AP_KVM_ONLINE.\n\nGate the read on the CPU's own ID_AA64PFR1_EL1 with the command-line\noverride applied, and on CONFIG_ARM64_MTE, which no register reflects.\nThe boot CPU stores its registers before init_cpu_features() strips an\nunsafe override, so clamp against the hardware value here too."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/arm64/include/asm/cpu.h", "arch/arm64/include/asm/cpufeature.h", "arch/arm64/kernel/cpufeature.c", "arch/arm64/kernel/cpuinfo.c"], "versions": [{"version": "f35abcbb8a084db4c24b66ccc8db0405c08e2f61", "lessThan": "d2d22ff377cd43f2e9660426ff22e3cd4c534637", "status": "affected", "versionType": "git"}, {"version": "f35abcbb8a084db4c24b66ccc8db0405c08e2f61", "lessThan": "5445d64199626974269fcdf347769ad44b0bb53b", "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/arm64/include/asm/cpu.h", "arch/arm64/include/asm/cpufeature.h", "arch/arm64/kernel/cpufeature.c", "arch/arm64/kernel/cpuinfo.c"], "versions": [{"version": "7.0", "status": "affected"}, {"version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "7.0", "versionEndExcluding": "7.2.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/d2d22ff377cd43f2e9660426ff22e3cd4c534637"}, {"url": "https://git.kernel.org/stable/c/5445d64199626974269fcdf347769ad44b0bb53b"}], "title": "arm64: Don't read GMID_EL1 when MTE is disabled", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["arch/arm64/include/asm/cpu.h", "arch/arm64/include/asm/cpufeature.h", "arch/arm64/kernel/cpufeature.c", "arch/arm64/kernel/cpuinfo.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "d2d22ff377cd43f2e9660426ff22e3cd4c534637", "status": "affected", "version": "f35abcbb8a084db4c24b66ccc8db0405c08e2f61", "versionType": "git"}, {"lessThan": "5445d64199626974269fcdf347769ad44b0bb53b", "status": "affected", "version": "f35abcbb8a084db4c24b66ccc8db0405c08e2f61", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["arch/arm64/include/asm/cpu.h", "arch/arm64/include/asm/cpufeature.h", "arch/arm64/kernel/cpufeature.c", "arch/arm64/kernel/cpuinfo.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.0"}, {"lessThan": "7.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: Don't read GMID_EL1 when MTE is disabled\n\n__cpuinfo_store_cpu() gates the GMID_EL1 read on the raw\nID_AA64PFR1_EL1, so it reads the register even when the kernel has\ndisabled MTE (CONFIG_ARM64_MTE=n or arm64.nomte). KVM sets HCR_EL2.TID5\nin that case, and pKVM injects an UNDEF the host cannot handle:\n\n Internal error: Oops - Undefined instruction: 0000000002000000 [#1] SMP\n pc : __cpuinfo_store_cpu+0xf4/0x264\n Kernel panic - not syncing: Attempted to kill the idle task!\n\nOnly pKVM reaches it, and only after a CPU is offlined and brought back\nonline: its CPU_ON relay sets the host HCR before the CPU enters EL1,\nwhile plain nVHE sets it at CPUHP_AP_KVM_ONLINE.\n\nGate the read on the CPU's own ID_AA64PFR1_EL1 with the command-line\noverride applied, and on CONFIG_ARM64_MTE, which no register reflects.\nThe boot CPU stores its registers before init_cpu_features() strips an\nunsafe override, so clamp against the hardware value here too."}], "id": "CVE-2026-89981", "lastModified": "2026-10-19T09:18:45.013", "metrics": {}, "published": "2026-09-16T11:17:09.037", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5445d64199626974269fcdf347769ad44b0bb53b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d2d22ff377cd43f2e9660426ff22e3cd4c534637"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f35abcbb8a084db4c24b66ccc8db0405c08e2f61,d2d22ff377cd43f2e9660426ff22e3cd4c534637)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f35abcbb8a084db4c24b66ccc8db0405c08e2f61,5445d64199626974269fcdf347769ad44b0bb53b)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "7.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.5,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3-rc2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-17T13:15:12.758170+00:00", "updated": "2026-09-18T07:30:05.835845+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-20"]}