Add emalloc2() -- like calloc() but w/o the bzero and with error/oflow

checking.

diff --git a/alloc.c b/alloc.c
index e2f50ff086420e2591ad2215457a89f108853fe8..d094915170e07597421e4d6eba24b3c820473cfa 100644 (file)
--- a/alloc.c
+++ b/alloc.c
@@ -55,6 +55,7 @@
 #if defined(HAVE_MALLOC_H) && !defined(STDC_HEADERS)
 # include <malloc.h>
 #endif /* HAVE_MALLOC_H && !STDC_HEADERS */
+#include <limits.h>
 
 #include "sudo.h"
 
@@ -62,6 +63,18 @@
 static const char rcsid[] = "$Sudo$";
 #endif /* lint */
 
+#ifndef SIZE_MAX
+# ifdef SIZE_T_MAX
+#  define SIZE_MAX     SIZE_T_MAX
+# else
+#  ifdef ULONG_MAX
+#   define SIZE_MAX    ULONG_MAX
+#  else
+#   define SIZE_MAX    ((unsigned long)-1)
+#  endif /* ULONG_MAX */
+# endif /* SIZE_T_MAX */
+#endif /* SIZE_MAX */
+
 extern char **Argv;            /* from sudo.c */
 
 /*
@@ -86,6 +99,34 @@ emalloc(size)
     return(ptr);
 }
 
+/*
+ * emalloc2() allocates nmemb * size bytes and exits with an error
+ * if overflow would occur or if the system malloc(3) fails.
+ */
+VOID *
+emalloc2(nmemb, size)
+    size_t nmemb;
+    size_t size;
+{
+    VOID *ptr;
+
+    if (nmemb == 0 || size == 0) {
+       (void) fprintf(stderr, "%s: internal error, tried to malloc(0)\n",
+           Argv[0]);
+       exit(1);
+    }
+    if (nmemb >= SIZE_MAX / size) {
+       (void) fprintf(stderr, "%s: internal error, emalloc2() overflow\n",
+           Argv[0]);
+       exit(1);
+    }
+    if ((ptr = (VOID *) malloc(nmemb * size)) == NULL) {
+       (void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
+       exit(1);
+    }
+    return(ptr);
+}
+
 /*
  * erealloc() calls the system realloc(3) and exits with an error if
  * realloc(3) fails.  You can call erealloc() with a NULL pointer even

diff --git a/sudo.h b/sudo.h
index 884f8f80b92474881393a0419affc9406abc4bb9..8201df7d204fb67216cd700199520e993a8e0d57 100644 (file)
--- a/sudo.h
+++ b/sudo.h
@@ -212,6 +212,7 @@ void pam_attempt_auth       __P((void));
 int yyparse            __P((void));
 void pass_warn         __P((FILE *));
 VOID *emalloc          __P((size_t));
+VOID *emalloc2         __P((size_t, size_t));
 VOID *erealloc         __P((VOID *, size_t));
 char *estrdup          __P((const char *));
 int easprintf          __P((char **, const char *, ...));