2 files changed, 8 insertions, 1 deletions

diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index 47f29b1d1846..e7814b74caf8 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -69,7 +69,7 @@ struct insn {
         const insn_byte_t *next_byte;
 };
 
-#define MAX_INSN_SIZE   16
+#define MAX_INSN_SIZE   15
 
 #define X86_MODRM_MOD(modrm) (((modrm) & 0xc0) >> 6)
 #define X86_MODRM_REG(modrm) (((modrm) & 0x38) >> 3)
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 5ea00ddc1825..8f72b334aea0 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -52,6 +52,13 @@
  */
 void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
 {
+        /*
+         * Instructions longer than MAX_INSN_SIZE (15 bytes) are invalid
+         * even if the input buffer is long enough to hold them.
+         */
+        if (buf_len > MAX_INSN_SIZE)
+                buf_len = MAX_INSN_SIZE;
+
         memset(insn, 0, sizeof(*insn));
         insn->kaddr = kaddr;
         insn->end_kaddr = kaddr + buf_len;