{"id":"CVE-2026-98546","state":"PUBLISHED","title":"arm64/boot: Disable trapping of PMZR_EL0 writes to EL2","description":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/boot: Disable trapping of PMZR_EL0 writes to EL2\n\n__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.\nPMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in\nHDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host\ntraps to EL2, where the nVHE hypervisor has no handler and BUG()s. The\nkernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU\ndriver set PMUSERENR_EL0.UEN for a task with a user-read event, so a\nwrite from EL0 reaches the trap and takes the host down without a panic\nmessage.\n\nAccumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already\ndoes for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9\nbits.","publishedAt":"2026-10-18T15:18:14.808Z","updatedAt":"2026-10-19T09:21:29.442Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"686d8f7b592f3466f44aea653c8147611b351c83","status":"affected","lessThan":"bb8c90c86441c090e9036f019cf1b4d7894a2c40","versionType":"git"},{"version":"858c7bfcb35e1100b58bb63c9f562d86e09418d9","status":"affected","lessThan":"071f51188a5d8ec10535541255587976d12fc7d8","versionType":"git"},{"version":"858c7bfcb35e1100b58bb63c9f562d86e09418d9","status":"affected","lessThan":"ce71865bf43f88bed9d9218e9218e537150be506","versionType":"git"},{"version":"858c7bfcb35e1100b58bb63c9f562d86e09418d9","status":"affected","lessThan":"2bc6b218717b9d08f466f88209251d54bc09b207","versionType":"git"},{"version":"882f78400322c0aec4b641a7168adad9a66bc0c2","status":"affected","versionType":"git"},{"version":"6.12.25","status":"affected","lessThan":"6.12.112","versionType":"semver"},{"version":"6.14.4","status":"affected","lessThan":"6.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/arch/arm64/booting.rst","arch/arm64/include/asm/el2_setup.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/arch/arm64/booting.rst","arch/arm64/include/asm/el2_setup.h"]}],"references":["https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40","https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8","https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506","https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98546.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98546","state":"PUBLISHED","datePublished":"2026-10-18T15:18:14.808Z","dateUpdated":"2026-10-19T09:21:29.442Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.356Z"},"containers":{"cna":{"title":"arm64/boot: Disable trapping of PMZR_EL0 writes to EL2","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/boot: Disable trapping of PMZR_EL0 writes to EL2\n\n__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.\nPMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in\nHDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host\ntraps to EL2, where the nVHE hypervisor has no handler and BUG()s. The\nkernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU\ndriver set PMUSERENR_EL0.UEN for a task with a user-read event, so a\nwrite from EL0 reaches the trap and takes the host down without a panic\nmessage.\n\nAccumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already\ndoes for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9\nbits."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"686d8f7b592f3466f44aea653c8147611b351c83","status":"affected","lessThan":"bb8c90c86441c090e9036f019cf1b4d7894a2c40","versionType":"git"},{"version":"858c7bfcb35e1100b58bb63c9f562d86e09418d9","status":"affected","lessThan":"071f51188a5d8ec10535541255587976d12fc7d8","versionType":"git"},{"version":"858c7bfcb35e1100b58bb63c9f562d86e09418d9","status":"affected","lessThan":"ce71865bf43f88bed9d9218e9218e537150be506","versionType":"git"},{"version":"858c7bfcb35e1100b58bb63c9f562d86e09418d9","status":"affected","lessThan":"2bc6b218717b9d08f466f88209251d54bc09b207","versionType":"git"},{"version":"882f78400322c0aec4b641a7168adad9a66bc0c2","status":"affected","versionType":"git"},{"version":"6.12.25","status":"affected","lessThan":"6.12.112","versionType":"semver"},{"version":"6.14.4","status":"affected","lessThan":"6.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/arch/arm64/booting.rst","arch/arm64/include/asm/el2_setup.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/arch/arm64/booting.rst","arch/arm64/include/asm/el2_setup.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40"},{"url":"https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8"},{"url":"https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506"},{"url":"https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:21:29.442Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.25","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14.4"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}