github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 01:55:51 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: x86: Harden is_64_bit_hypercall() against bugs on 32-bit kernels

Browse Source 
Unconditionally return %false for is_64_bit_hypercall() on 32-bit kernels
to guard against incorrectly setting guest_state_protected, and because
in a (very) hypothetical world where 32-bit KVM supports protected guests,
assuming a hypercall was made in 64-bit mode is flat out wrong.

Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://patch.msgid.link/20260529222223.870923-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson 2026-05-29 15:21:55 -07:00
parent b6a0fdf2bb
commit 879fffc094
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/kvm/regs.h
View File

@ -39,12 +39,16 @@ static inline bool is_64_bit_mode(struct kvm_vcpu *vcpu)
static inline bool is_64_bit_hypercall(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
/*
* If running with protected guest state, the CS register is not
* accessible. The hypercall register values will have had to been
* provided in 64-bit mode, so assume the guest is in 64-bit.
*/
return vcpu->arch.guest_state_protected || is_64_bit_mode(vcpu);
#else
return false;
#endif
}
static __always_inline unsigned long kvm_reg_mode_mask(struct kvm_vcpu *vcpu)