X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fsrc%2Fstring.c;h=64d14439e6bab3c2378e8bf594c40a2423d6348c;hb=25f3b885dbfd1ba330521c8fe106876667a31bb7;hp=cb913242092e28e3e267a871b69e388eb77d0c3e;hpb=320fe6140189f08168dce2deca19821b4237e747;p=user%2Fhenk%2Fcode%2Fexim.git

diff --git a/src/src/string.c b/src/src/string.c
index cb9132420..64d14439e 100644
--- a/src/src/string.c
+++ b/src/src/string.c
@@ -1094,7 +1094,16 @@ existing length of the string. */
 
 unsigned inc = oldsize < 4096 ? 127 : 1023;
 
+if (g->ptr < 0 || g->ptr > g->size || g->size >= INT_MAX/2)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+    "internal error in gstring_grow (ptr %d size %d)", g->ptr, g->size);
+
 if (count <= 0) return;
+
+if (count >= INT_MAX/2 - g->ptr)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+    "internal error in gstring_grow (ptr %d count %d)", g->ptr, count);
+
 g->size = (p + count + inc + 1) & ~inc;		/* one for a NUL */
 
 /* Try to extend an existing allocation. If the result of calling
@@ -1143,6 +1152,10 @@ string_catn(gstring * g, const uschar *s, int count)
 int p;
 BOOL srctaint = is_tainted(s);
 
+if (count < 0)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+    "internal error in string_catn (count %d)", count);
+
 if (!g)
   {
   unsigned inc = count < 4096 ? 127 : 1023;
@@ -1152,8 +1165,12 @@ if (!g)
 else if (srctaint && !is_tainted(g->s))
   gstring_rebuffer(g);
 
+if (g->ptr < 0 || g->ptr > g->size)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+    "internal error in string_catn (ptr %d size %d)", g->ptr, g->size);
+
 p = g->ptr;
-if (p + count >= g->size)
+if (count >= g->size - p)
   gstring_grow(g, count);
 
 /* Because we always specify the exact number of characters to copy, we can