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| author | Maxim Levitsky <mlevitsk@redhat.com> | 2022-10-25 14:47:32 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-10-28 12:10:30 +0200 |
| commit | 696db303e54f7352623d9f640e6c51d8fa9d5588 (patch) | |
| tree | b9b0ef36715305cf7aaec067d78ece54eca06a05 | |
| parent | KVM: x86: emulator: update the emulation mode after CR0 write (diff) | |
| download | linux-696db303e54f7352623d9f640e6c51d8fa9d5588.tar.xz linux-696db303e54f7352623d9f640e6c51d8fa9d5588.zip | |
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.
Fixes: b443183a25ab61 ("KVM: x86: Reduce the number of emulator GPRs to '8' for 32-bit KVM")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221025124741.228045-15-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/emulate.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 2954c046740b..4a43261d25a2 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2461,7 +2461,7 @@ static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt, ctxt->eflags = GET_SMSTATE(u32, smstate, 0x7ff4) | X86_EFLAGS_FIXED; ctxt->_eip = GET_SMSTATE(u32, smstate, 0x7ff0); - for (i = 0; i < NR_EMULATOR_GPRS; i++) + for (i = 0; i < 8; i++) *reg_write(ctxt, i) = GET_SMSTATE(u32, smstate, 0x7fd0 + i * 4); val = GET_SMSTATE(u32, smstate, 0x7fcc); @@ -2518,7 +2518,7 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, u16 selector; int i, r; - for (i = 0; i < NR_EMULATOR_GPRS; i++) + for (i = 0; i < 16; i++) *reg_write(ctxt, i) = GET_SMSTATE(u64, smstate, 0x7ff8 - i * 8); ctxt->_eip = GET_SMSTATE(u64, smstate, 0x7f78); |