3.17-stable review patch. If anyone has any objections, please let me know.
------------------ From: Nadav Amit <[email protected]> commit d29b9d7ed76c0b961603ca692b8a562556a20212 upstream. The emulator could reuse an op->type from a previous instruction for some immediate values. If it mistakenly considers the operands as memory operands, it will performs a memory read and overwrite op->val. Consider for instance the ROR instruction - src2 (the number of times) would be read from memory instead of being used as immediate. Mark every immediate operand as such to avoid this problem. Fixes: c44b4c6ab80eef3a9c52c7b3f0c632942e6489aa Signed-off-by: Nadav Amit <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kvm/emulate.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4272,6 +4272,7 @@ static int decode_operand(struct x86_emu fetch_register_operand(op); break; case OpCL: + op->type = OP_IMM; op->bytes = 1; op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff; break; @@ -4279,6 +4280,7 @@ static int decode_operand(struct x86_emu rc = decode_imm(ctxt, op, 1, true); break; case OpOne: + op->type = OP_IMM; op->bytes = 1; op->val = 1; break; @@ -4337,21 +4339,27 @@ static int decode_operand(struct x86_emu ctxt->memop.bytes = ctxt->op_bytes + 2; goto mem_common; case OpES: + op->type = OP_IMM; op->val = VCPU_SREG_ES; break; case OpCS: + op->type = OP_IMM; op->val = VCPU_SREG_CS; break; case OpSS: + op->type = OP_IMM; op->val = VCPU_SREG_SS; break; case OpDS: + op->type = OP_IMM; op->val = VCPU_SREG_DS; break; case OpFS: + op->type = OP_IMM; op->val = VCPU_SREG_FS; break; case OpGS: + op->type = OP_IMM; op->val = VCPU_SREG_GS; break; case OpImplicit: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
