Make macro safer when strlcpy() is not available

Macro would previously trigger an out-of-bound write if passed a size of zero. Also, the size was not protected against a possible operator precedence issue. Signed-off-by: Loren M. Lang <[email protected]> Signed-off-by: Aaron Conole <[email protected]>
intel · Aug 16, 2024 · 6c947ee · 6c947ee
1 parent 96106e8
commit 6c947ee
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/include/lldp.h b/include/lldp.h
@@ -58,8 +58,10 @@ typedef __u64 u64;
 #else
 #define STRNCPY_TERMINATED(DEST, SRC, N) \
   do { \
-    strncpy (DEST, SRC, N - 1); \
-    DEST[N - 1] = '\0'; \
+    if((N) > 0) { \
+      strncpy (DEST, SRC, (N) - 1); \
+      DEST[(N) - 1] = '\0'; \
+    } \
   } while (false)
 #endif