From: Eduardo Habkost <[email protected]> A new register was added to the load/save list on commit d283d5a65a2bdcc570065267be21848bd6fe3d78, but MSR_COUNT was not updated, leading to potential stack corruption on kvm_arch_save_regs().
The following registers are saved by kvm_arch_save_regs(): 1) MSR_IA32_SYSENTER_CS 2) MSR_IA32_SYSENTER_ESP 3) MSR_IA32_SYSENTER_EIP 4) MSR_STAR 5) MSR_IA32_TSC 6) MSR_VM_HSAVE_PA 7) MSR_CSTAR (x86_64 only) 8) MSR_KERNELGSBASE (x86_64 only) 9) MSR_FMASK (x86_64 only) 10) MSR_LSTAR (x86_64 only) Signed-off-by: Eduardo Habkost <[email protected]> Signed-off-by: Marcelo Tosatti <[email protected]> diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c index fffcfd8..475151d 100644 --- a/qemu-kvm-x86.c +++ b/qemu-kvm-x86.c @@ -842,9 +842,9 @@ static int get_msr_entry(struct kvm_msr_entry *entry, CPUState *env) } #ifdef TARGET_X86_64 -#define MSR_COUNT 9 +#define MSR_COUNT 10 #else -#define MSR_COUNT 5 +#define MSR_COUNT 6 #endif static void set_v8086_seg(struct kvm_segment *lhs, const SegmentCache *rhs) @@ -986,6 +986,7 @@ void kvm_arch_load_regs(CPUState *env) /* msrs */ n = 0; + /* Remember to increase MSR_COUNT if you add new registers below */ set_msr_entry(&msrs[n++], MSR_IA32_SYSENTER_CS, env->sysenter_cs); set_msr_entry(&msrs[n++], MSR_IA32_SYSENTER_ESP, env->sysenter_esp); set_msr_entry(&msrs[n++], MSR_IA32_SYSENTER_EIP, env->sysenter_eip); @@ -1163,6 +1164,7 @@ void kvm_arch_save_regs(CPUState *env) /* msrs */ n = 0; + /* Remember to increase MSR_COUNT if you add new registers below */ msrs[n++].index = MSR_IA32_SYSENTER_CS; msrs[n++].index = MSR_IA32_SYSENTER_ESP; msrs[n++].index = MSR_IA32_SYSENTER_EIP; -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
