From 838ec0a2ca94bbff019207851166574547a1b334 Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@courtesan.com>
Date: Wed, 12 Mar 2003 21:51:39 +0000
Subject: [PATCH] Add erealloc3(), a realloc() version of emalloc2().

---
 alloc.c | 35 ++++++++++++++++++++++++++++++++++-
 sudo.h  |  1 +
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/alloc.c b/alloc.c
index d09491517..dbd973d38 100644
--- a/alloc.c
+++ b/alloc.c
@@ -120,7 +120,8 @@ emalloc2(nmemb, size)
 	    Argv[0]);
 	exit(1);
     }
-    if ((ptr = (VOID *) malloc(nmemb * size)) == NULL) {
+    size *= nmemb;
+    if ((ptr = (VOID *) malloc(size)) == NULL) {
 	(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
 	exit(1);
     }
@@ -151,6 +152,38 @@ erealloc(ptr, size)
     return(ptr);
 }
 
+/*
+ * erealloc3() realloc(3)s nmemb * size bytes and exits with an error
+ * if overflow would occur or if the system malloc(3)/realloc(3) fails.
+ * You can call erealloc() with a NULL pointer even if the system realloc(3)
+ * does not support this.
+ */
+VOID *
+erealloc3(ptr, nmemb, size)
+    VOID *ptr;
+    size_t nmemb;
+    size_t size;
+{
+
+    if (nmemb == 0 || size == 0) {
+	(void) fprintf(stderr, "%s: internal error, tried to realloc(0)\n",
+	    Argv[0]);
+	exit(1);
+    }
+    if (nmemb >= SIZE_MAX / size) {
+	(void) fprintf(stderr, "%s: internal error, erealloc3() overflow\n",
+	    Argv[0]);
+	exit(1);
+    }
+    size *= nmemb;
+    ptr = ptr ? (VOID *) realloc(ptr, size) : (VOID *) malloc(size);
+    if (ptr == NULL) {
+	(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
+	exit(1);
+    }
+    return(ptr);
+}
+
 /*
  * estrdup() is like strdup(3) except that it exits with an error if
  * malloc(3) fails.  NOTE: unlike strdup(3), estrdup(NULL) is legal.
diff --git a/sudo.h b/sudo.h
index 8201df7d2..a56281258 100644
--- a/sudo.h
+++ b/sudo.h
@@ -214,6 +214,7 @@ void pass_warn		__P((FILE *));
 VOID *emalloc		__P((size_t));
 VOID *emalloc2		__P((size_t, size_t));
 VOID *erealloc		__P((VOID *, size_t));
+VOID *erealloc3		__P((VOID *, size_t, size_t));
 char *estrdup		__P((const char *));
 int easprintf		__P((char **, const char *, ...));
 int evasprintf		__P((char **, const char *, va_list));
-- 
2.40.0