In the Linux kernel, the following vulnerability has been resolved: KVM: x86: smm: number of GPRs in the SMRAM image depends on the image format On 64 bit host, if the guest doesn't have X86_FEATURE_LM, KVM will access 16 gprs to 32-bit smram image, causing out-ouf-bound ram access. On 32 bit host, the rsm_load_state_64/enter_smm_save_state_64 is compiled out, thus access overflow can't happen.