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| author | Nadav Amit <namit@cs.technion.ac.il> | 2014-12-25 02:52:17 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-01-08 22:48:04 +0100 |
| commit | 3313bc4ee83c4e2870d8e83800c6064b0d215679 (patch) | |
| tree | eda0f8afbeadc3fbb84290dc92949c9d678c137a | |
| parent | fa4a2c080e37d362ae603f4ea157fe779bd85cb5 (diff) | |
| download | linux-3313bc4ee83c4e2870d8e83800c6064b0d215679.tar.gz | |
KVM: x86: pop sreg accesses only 2 bytes
Although pop sreg updates RSP according to the operand size, only 2 bytes are read. The current behavior may result in incorrect #GP or #PF exceptions. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/emulate.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index feaba468cce6..abe95d2e6848 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1828,12 +1828,14 @@ static int em_pop_sreg(struct x86_emulate_ctxt *ctxt) unsigned long selector; int rc; - rc = emulate_pop(ctxt, &selector, ctxt->op_bytes); + rc = emulate_pop(ctxt, &selector, 2); if (rc != X86EMUL_CONTINUE) return rc; if (ctxt->modrm_reg == VCPU_SREG_SS) ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; + if (ctxt->op_bytes > 2) + rsp_increment(ctxt, ctxt->op_bytes - 2); rc = load_segment_descriptor(ctxt, (u16)selector, seg); return rc; |