{"id":"CVE-2026-98546","published":"2026-10-18T16:17:06.517","lastModified":"2026-10-19T10:19:10.600","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/071f51188a5d8ec10535541255587976d12fc7d8","tags":[]},{"url":"https://git.kernel.org/stable/c/2bc6b218717b9d08f466f88209251d54bc09b207","tags":[]},{"url":"https://git.kernel.org/stable/c/bb8c90c86441c090e9036f019cf1b4d7894a2c40","tags":[]},{"url":"https://git.kernel.org/stable/c/ce71865bf43f88bed9d9218e9218e537150be506","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}