From 7aaddf52cd98589fb0c3ab72a393f8411838438a Mon Sep 17 00:00:00 2001 From: "Emden R. Gansner" Date: Fri, 4 Oct 2013 09:06:39 -0400 Subject: [PATCH] Fix buffer overflow problem when reporting a syntax error with a very long input line --- lib/cgraph/scan.l | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/lib/cgraph/scan.l b/lib/cgraph/scan.l index 3cfde0f..2efd203 100644 --- a/lib/cgraph/scan.l +++ b/lib/cgraph/scan.l @@ -16,6 +16,7 @@ %{ #include #include +#include #include #define GRAPH_EOF_TOKEN '@' /* lex class must be defined below */ /* this is a workaround for linux flex */ @@ -191,13 +192,21 @@ ID ({NAME}|{NUMBER}) %% void yyerror(char *str) { + unsigned char xbuf[BUFSIZ]; char buf[BUFSIZ]; - if (InputFile) - sprintf(buf,"%s:%d: %s in line %d near '%s'\n",InputFile, line_num, - str,line_num,yytext); - else - sprintf(buf," %s in line %d near '%s'\n", str,line_num,yytext); - agerr(AGWARN,buf); + agxbuf xb; + + agxbinit(&xb, BUFSIZ, xbuf); + if (InputFile) { + agxbput (&xb, InputFile); + agxbput (&xb, ": "); + } + sprintf(buf," %s in line %d near '", str,line_num); + agxbput (&xb, buf); + agxbput (&xb, yytext); + agxbput (&xb,"'\n"); + agerr(AGWARN,agxbuse(&xb)); + agxbfree(&xb); } /* must be here to see flex's macro defns */ void aglexeof() { unput(GRAPH_EOF_TOKEN); } -- 1.8.5.1