diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index ff20b35e98dddb84249ec2ddbba1ecf6d345004e..d2490c366e33018fb57aeac5ffd36fef619eea0b 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -156,8 +156,8 @@ static int identify_insn(struct insn *insn)
 	if (!insn->modrm.nbytes)
 		return -EINVAL;
 
-	/* All the instructions of interest start with 0x0f. */
-	if (insn->opcode.bytes[0] != 0xf)
+	/* The instructions of interest have 2-byte opcodes: 0F 00 or 0F 01. */
+	if (insn->opcode.nbytes < 2 || insn->opcode.bytes[0] != 0xf)
 		return -EINVAL;
 
 	if (insn->opcode.bytes[1] == 0x1) {