]> xenbits.xensource.com Git - xen.git/commit
x86/cpu: Validate CPUID leaf 0x2 EDX output
authorAhmed S. Darwish <darwi@linutronix.de>
Tue, 8 Apr 2025 07:37:38 +0000 (09:37 +0200)
committerJan Beulich <jbeulich@suse.com>
Tue, 8 Apr 2025 07:37:38 +0000 (09:37 +0200)
commita47b44a8f0a58a6015faf6465921cd203f0b51d1
tree7a583b1488c10c71b34a025aad35a61c62586953
parent6a884750f3b86a45ee5ffbd825c346fcbce86080
x86/cpu: Validate CPUID leaf 0x2 EDX output

CPUID leaf 0x2 emits one-byte descriptors in its four output registers
EAX, EBX, ECX, and EDX.  For these descriptors to be valid, the most
significant bit (MSB) of each register must be clear.

Leaf 0x2 parsing at intel.c only validated the MSBs of EAX, EBX, and
ECX, but left EDX unchecked.

Validate EDX's most-significant bit as well.

Fixes: 1aa6feb63bfd ("Port CPU setup code from Linux 2.6")
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250304085152.51092-3-darwi@linutronix.de
Use ARRAY_SIZE() though.

Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 1881148215c6
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
xen/arch/x86/cpu/intel_cacheinfo.c