In the Linux kernel, the following vulnerability has been resolved: x86/mtrr: Check if fixed MTRRs exist before saving them MTRRs have an obsolete fixed variant for fine grained caching control of the 640K-1MB region that uses separate MSRs. This fixed variant has a separate capability bit in the MTRR capability MSR. So far all x86 CPUs which support MTRR have this separate bit set, so it went unnoticed that mtrr_save_state() does not check the capability bit before accessing the fixed MTRR MSRs. Though on a CPU that does not support the fixed MTRR capability this results in a #GP. The #GP itself is harmless because the RDMSR fault is handled gracefully, but results in a WARN_ON(). Add the missing capability check to prevent this.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | < 6.1.106-1 | linux_6.1.106-1_all.deb |
Debian | 11 | all | linux | <= 5.10.223-1 | linux_5.10.223-1_all.deb |
Debian | 999 | all | linux | < 6.10.6-1 | linux_6.10.6-1_all.deb |
Debian | 13 | all | linux | < 6.10.6-1 | linux_6.10.6-1_all.deb |