2 files changed, 12 insertions, 5 deletions

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 46ac9a50528d..8eefcf7e95eb 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -382,7 +382,7 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
 }
 
 extern int hex_to_bin(char ch);
-extern void hex2bin(u8 *dst, const char *src, size_t count);
+extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
 
 /*
  * General tracing related utility functions - trace_printk(),
diff --git a/lib/hexdump.c b/lib/hexdump.c
index f5fe6ba7a3ab..51d5ae210244 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -38,14 +38,21 @@ EXPORT_SYMBOL(hex_to_bin);
  * @dst: binary result
  * @src: ascii hexadecimal string
  * @count: result length
+ *
+ * Return 0 on success, -1 in case of bad input.
  */
-void hex2bin(u8 *dst, const char *src, size_t count)
+int hex2bin(u8 *dst, const char *src, size_t count)
 {
         while (count--) {
-                *dst = hex_to_bin(*src++) << 4;
-                *dst += hex_to_bin(*src++);
-                dst++;
+                int hi = hex_to_bin(*src++);
+                int lo = hex_to_bin(*src++);
+
+                if ((hi < 0) || (lo < 0))
+                        return -1;
+
+                *dst++ = (hi << 4) | lo;
         }
+        return 0;
 }
 EXPORT_SYMBOL(hex2bin);