Add sprintf() check

1 files changed, 15 insertions, 1 deletions

diff --git a/include/stdio.h b/include/stdio.h
index 1217a0f..41b09e1 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -41,7 +41,21 @@ __fortify_vsnprintf(char *s, size_t n, const char *fmt, __builtin_va_list ap)
         size_t bos = __builtin_object_size(s, 0); \
         if (_n > bos) \
                 __builtin_trap(); \
-        snprintf(s, _n, fmt, ## __VA_ARGS__); \
+        (snprintf)(s, _n, fmt, ## __VA_ARGS__); \
+})
+
+#undef sprintf
+#define sprintf(s, fmt, ...) ({ \
+        size_t bos = __builtin_object_size(s, 0); \
+        int r; \
+        if (bos != -1) { \
+                r = (snprintf)(s, bos, fmt, ## __VA_ARGS__); \
+                if (r == -1 || r >= bos) \
+                        __builtin_trap(); \
+        } else { \
+                r = (sprintf)(s, fmt, ## __VA_ARGS__); \
+        } \
+        r; \
 })
 
 #endif