Update util/xmalloc.c from rra-c-util

[kerberos/krb5-strength.git] / util / xmalloc.c

diff --git a/util/xmalloc.c b/util/xmalloc.c
index fc6839eef939eb5f1e1ffe41b48f916a8af8a989..2e3e1246a21f975d9fa066cc45ba8fa4b35cd71c 100644 (file)
--- a/util/xmalloc.c
+++ b/util/xmalloc.c
@@ -62,13 +62,12 @@
  * The canonical version of this file is maintained in the rra-c-util package,
  * which can be found at <https://www.eyrie.org/~eagle/software/rra-c-util/>.
  *
- * Copyright 2015 Russ Allbery <eagle@eyrie.org>
- * Copyright 2012, 2013, 2014
+ * Written by Russ Allbery <eagle@eyrie.org>
+ * Copyright 2015, 2023 Russ Allbery <eagle@eyrie.org>
+ * Copyright 2012-2014
  *     The Board of Trustees of the Leland Stanford Junior University
- * Copyright (c) 2004, 2005, 2006
- *     by Internet Systems Consortium, Inc. ("ISC")
- * Copyright (c) 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
- *     2002, 2003 by The Internet Software Consortium and Rich Salz
+ * Copyright 2004-2006 Internet Systems Consortium, Inc. ("ISC")
+ * Copyright 1991, 1994-2003 The Internet Software Consortium and Rich Salz
  *
  * This code is derived from software contributed to the Internet Software
  * Consortium by Rich Salz.
@@ -84,6 +83,8 @@
  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  * PERFORMANCE OF THIS SOFTWARE.
+ *
+ * SPDX-License-Identifier: ISC
  */
 
 #include <config.h>
@@ -120,7 +121,7 @@ x_malloc(size_t size, const char *file, int line)
     real_size = (size > 0) ? size : 1;
     p = malloc(real_size);
     while (p == NULL) {
-        (*xmalloc_error_handler)("malloc", size, file, line);
+        xmalloc_error_handler("malloc", size, file, line);
         p = malloc(real_size);
     }
     return p;
@@ -136,7 +137,7 @@ x_calloc(size_t n, size_t size, const char *file, int line)
     size = (size > 0) ? size : 1;
     p = calloc(n, size);
     while (p == NULL) {
-        (*xmalloc_error_handler)("calloc", n * size, file, line);
+        xmalloc_error_handler("calloc", n * size, file, line);
         p = calloc(n, size);
     }
     return p;
@@ -149,11 +150,27 @@ x_realloc(void *p, size_t size, const char *file, int line)
     void *newp;
 
     newp = realloc(p, size);
-    while (newp == NULL && size > 0) {
-        (*xmalloc_error_handler)("realloc", size, file, line);
+    if (size == 0)
+        return newp;
+
+        /*
+         * GCC 13.2.0 (and some earlier versions) misdiagnose this error
+         * handling as a use-after-free of p, but the C standard guarantees
+         * that if realloc fails (which is true in every case when it returns
+         * NULL when size > 0), p is unchanged and still valid.
+         */
+#if __GNUC__ >= 12 && !defined(__clang__)
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wuse-after-free"
+#endif
+    while (newp == NULL) {
+        xmalloc_error_handler("realloc", size, file, line);
         newp = realloc(p, size);
     }
     return newp;
+#if __GNUC__ >= 12 && !defined(__clang__)
+#    pragma GCC diagnostic pop
+#endif
 }
 
 
@@ -163,10 +180,27 @@ x_reallocarray(void *p, size_t n, size_t size, const char *file, int line)
     void *newp;
 
     newp = reallocarray(p, n, size);
-    while (newp == NULL && size > 0 && n > 0) {
-        (*xmalloc_error_handler)("reallocarray", n * size, file, line);
+    if (size == 0 || n == 0)
+        return newp;
+
+        /*
+         * GCC 13.2.0 (and some earlier versions) misdiagnose this error
+         * handling as a use-after-free of p, but the documentation of
+         * reallocarray guarantees that if reallocarray fails (which is true in
+         * every case when it returns NULL when size > 0 and n > 0), p is
+         * unchanged and still valid.
+         */
+#if __GNUC__ >= 12 && !defined(__clang__)
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wuse-after-free"
+#endif
+    while (newp == NULL) {
+        xmalloc_error_handler("reallocarray", n * size, file, line);
         newp = reallocarray(p, n, size);
     }
+#if __GNUC__ >= 12 && !defined(__clang__)
+#    pragma GCC diagnostic pop
+#endif
     return newp;
 }
 
@@ -180,7 +214,7 @@ x_strdup(const char *s, const char *file, int line)
     len = strlen(s) + 1;
     p = malloc(len);
     while (p == NULL) {
-        (*xmalloc_error_handler)("strdup", len, file, line);
+        xmalloc_error_handler("strdup", len, file, line);
         p = malloc(len);
     }
     memcpy(p, s, len);
@@ -201,12 +235,12 @@ x_strndup(const char *s, size_t size, const char *file, int line)
     char *copy;
 
     /* Don't assume that the source string is nul-terminated. */
-    for (p = s; (size_t)(p - s) < size && *p != '\0'; p++)
+    for (p = s; (size_t) (p - s) < size && *p != '\0'; p++)
         ;
     length = p - s;
     copy = malloc(length + 1);
     while (copy == NULL) {
-        (*xmalloc_error_handler)("strndup", length + 1, file, line);
+        xmalloc_error_handler("strndup", length + 1, file, line);
         copy = malloc(length + 1);
     }
     memcpy(copy, s, length);
@@ -230,7 +264,7 @@ x_vasprintf(char **strp, const char *fmt, va_list args, const char *file,
         status = vsnprintf(NULL, 0, fmt, args_copy);
         va_end(args_copy);
         status = (status < 0) ? 0 : status + 1;
-        (*xmalloc_error_handler)("vasprintf", status, file, line);
+        xmalloc_error_handler("vasprintf", status, file, line);
         va_copy(args_copy, args);
         status = vasprintf(strp, fmt, args_copy);
         va_end(args_copy);
@@ -254,7 +288,7 @@ x_asprintf(char **strp, const char *file, int line, const char *fmt, ...)
         status = vsnprintf(NULL, 0, fmt, args_copy);
         va_end(args_copy);
         status = (status < 0) ? 0 : status + 1;
-        (*xmalloc_error_handler)("asprintf", status, file, line);
+        xmalloc_error_handler("asprintf", status, file, line);
         va_copy(args_copy, args);
         status = vasprintf(strp, fmt, args_copy);
         va_end(args_copy);
@@ -277,7 +311,7 @@ x_asprintf(char **strp, const char *fmt, ...)
         status = vsnprintf(NULL, 0, fmt, args_copy);
         va_end(args_copy);
         status = (status < 0) ? 0 : status + 1;
-        (*xmalloc_error_handler)("asprintf", status, __FILE__, __LINE__);
+        xmalloc_error_handler("asprintf", status, __FILE__, __LINE__);
         va_copy(args_copy, args);
         status = vasprintf(strp, fmt, args_copy);
         va_end(args_copy);