{"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":"2026-09-16T10:32:58.056Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-16T10:32:58.056Z"},"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-rc2","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-rc2"}]}]}],"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"}}}}