Check snprintf() rval for < 0; OK deraadt@

1 files changed, 6 insertions, 7 deletions

diff --git a/libexec/telnetd/global.c b/libexec/telnetd/global.c
index 63c2b57812d..d5dd39b556c 100644
--- a/libexec/telnetd/global.c
+++ b/libexec/telnetd/global.c
@@ -93,15 +93,14 @@ int
 output_data (const char *format, ...)
 {
   va_list args;
-  size_t remaining, ret;
+  size_t remaining;
+  int n;
 
   va_start(args, format);
   remaining = BUFSIZ - (nfrontp - netobuf);
-  ret = vsnprintf (nfrontp,
-		   remaining,
-		   format,
-		   args);
-  nfrontp += ((ret < remaining - 1) ? ret : remaining - 1);
+  if ((n = vsnprintf(nfrontp, remaining, format, args)) >= remaining || n < 0)
+    n = strlen(nfrontp);
+  nfrontp += n;
   va_end(args);
-  return ret;
+  return n;
 }