CVE-2026-98546
Received
Received - Intake
arm64/boot: Fix PMZR_EL0 Trap Handling in EL2
Vulnerability report for CVE-2026-98546, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-18
Last updated on: 2026-10-18
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
arm64/boot: Disable trapping of PMZR_EL0 writes to EL2
__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.
Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 686d8f7b592f3466f44aea653c8147611b351c83 |
| Linux | Linux | 858c7bfcb35e1100b58bb63c9f562d86e09418d9 |
| Linux | Linux | 858c7bfcb35e1100b58bb63c9f562d86e09418d9 |
| Linux | Linux | 858c7bfcb35e1100b58bb63c9f562d86e09418d9 |
| Linux | Linux | 882f78400322c0aec4b641a7168adad9a66bc0c2 |
| Linux | Linux | 6.12.25 |
| Linux | Linux | 6.14.4 |
| Linux | Linux | 6.15 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
