Fix $regex<n> use-after-free. Bug 2915

[exim.git] / src / src / dummies.c

diff --git a/src/src/dummies.c b/src/src/dummies.c
index 2e1ad11f5864fb1c1e24a9ba3bba3a9248719bbb..38b514b6c46946c8192216c73f5c48656e215df0 100644 (file)
--- a/src/src/dummies.c
+++ b/src/src/dummies.c
@@ -3,6 +3,7 @@
 *************************************************/
 
 /* Copyright (c) University of Cambridge 1995 - 2009 */
+/* Copyright (c) The Exim Maintainers 2021 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* This file is not part of the main Exim code. There are little bits of test
@@ -20,7 +21,7 @@ alternates. */
 /* We don't have the full Exim headers dragged in, but this function
 is used for debugging output. */
 
-extern gstring * string_vformat(gstring *, BOOL, const char *, va_list);
+extern gstring * string_vformat(gstring *, unsigned, const char *, va_list);
 
 
 /*************************************************
@@ -47,8 +48,6 @@ va_start(ap, format);
 vfprintf(stderr, format, ap);
 fprintf(stderr, "\n");
 va_end(ap);
-selector = selector;     /* Keep picky compilers happy */
-flags = flags;
 }
 
 
@@ -56,7 +55,9 @@ flags = flags;
 *      Handle calls to print debug output        *
 *************************************************/
 
-/* The message just gets written to stderr
+/* The message just gets written to stderr.
+We use tainted memory to format into just so that we can handle
+tainted arguments.
 
 Arguments:
   format    a printf() format
@@ -69,12 +70,12 @@ void
 debug_printf(char *format, ...)
 {
 va_list ap;
-gstring * g = string_get(1024);
-void * reset_point = g;
+rmark reset_point = store_mark();
+gstring * g = string_get_tainted(1024, TRUE);
 
 va_start(ap, format);
 
-if (!string_vformat(g, FALSE, format, ap))
+if (!string_vformat(g, 0, format, ap))
   {
   char * s = "**** debug string overflowed buffer ****\n";
   char * p = CS g->s + g->ptr;
@@ -101,7 +102,6 @@ extern int sigalrm_seen;
 void
 sigalrm_handler(int sig)
 {
-sig = sig;            /* Keep picky compilers happy */
 sigalrm_seen = TRUE;
 }
 
@@ -114,19 +114,12 @@ sigalrm_seen = TRUE;
 int
 header_checkname(void *h, char *name, int len)
 {
-h = h;            /* Keep picky compilers happy */
-name = name;
-len = len;
 return 0;
 }
 
 void
 directory_make(char *parent, char *name, int mode, int panic)
 {
-parent = parent;  /* Keep picky compilers happy */
-name = name;
-mode = mode;
-panic = panic;
 }
 
 void
@@ -138,10 +131,6 @@ host_build_sender_fullhost(void) { }
 char *
 host_ntoa(int type, const void *arg, char *buffer, int *portptr)
 {
-type = type;      /* Keep picky compilers happy */
-arg = arg;
-buffer = buffer;
-portptr = portptr;
 return NULL;
 }
 #endif