nightmaremail

commit ad73be052759c9472bcd1b871bd402eacf80da78
parent 628b8661ef57c9d5badd1a808482f88a31c4da4d
Author: Rolf Eike Beer <eike@sf-mail.de>
Date:   Tue, 12 May 2020 20:22:22 +0200

fix string length calculation overflow in quote() helper

Diffstat:
M
Makefile
 | 
2
+-
M
quote.c
 | 
11
++++++++++-

2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1659,7 +1659,7 @@ tryutmpx.c compile load qtmp.h1 qtmp.h2
 	rm -f tryutmpx.o tryutmpx
 
 quote.o: \
-compile quote.c stralloc.h gen_alloc.h str.h quote.h
+compile quote.c stralloc.h gen_alloc.h str.h quote.h oflops.h error.h
 	./compile quote.c
 
 rcpthosts.o: \
diff --git a/quote.c b/quote.c
@@ -1,3 +1,5 @@
+#include "error.h"
+#include "oflops.h"
 #include "stralloc.h"
 #include "str.h"
 #include "quote.h"
@@ -23,8 +25,15 @@ stralloc *sain;
  char ch;
  int i;
  int j;
+ unsigned int nlen;
 
- if (!stralloc_ready(saout,sain->len * 2 + 2)) return 0;
+ /* make sure the size calculation below does not overflow */
+ if (__builtin_mul_overflow(sain->len, 2, &nlen) ||
+     __builtin_add_overflow(nlen, 2, &nlen)) {
+   errno = error_nomem;
+   return 0;
+ }
+ if (!stralloc_ready(saout,nlen)) return 0;
  j = 0;
  saout->s[j++] = '"';
  for (i = 0;i < sain->len;++i)