From: "Barak A. Pearlmutter" Date: Sun, 25 Feb 2018 16:51:35 +0000 Subject: format security sprintf MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Squash potential buffer overflow noticed by GCC. Note that even if this is not an actual danger, a false positive can cause FTBFS in a high security environment. open.c: In function ‘fk_open’: open.c:222:28: warning: ‘%ld’ directive writing between 1 and 11 bytes into a region of size 5 [-Wformat-overflow=] (void) sprintf(nbuf,"fort.%ld",(long)n); ^~~ open.c:222:22: note: directive argument in the range [-2147483648, 2147483647] (void) sprintf(nbuf,"fort.%ld",(long)n); ^~~~~~~~~~ open.c:222:2: note: ‘sprintf’ output between 7 and 17 bytes into a destination of size 10 (void) sprintf(nbuf,"fort.%ld",(long)n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ --- open.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/open.c b/open.c index a06428d..288990c 100644 --- a/open.c +++ b/open.c @@ -282,7 +282,7 @@ fk_open(seq,fmt,n) ftnint n; #else fk_open(int seq, int fmt, ftnint n) #endif -{ char nbuf[10]; +{ char nbuf[17]; olist a; (void) sprintf(nbuf,"fort.%ld",(long)n); a.oerr=1;