svn commit: r330081 - stable/11/lib/libc/gen

[Kyle Evans]

Author: kevans
Date: Tue Feb 27 19:24:06 2018
New Revision: 330081
URL: https://svnweb.freebsd.org/changeset/base/330081

Log:
  MFC r318304: getusershell: don't write paste end of buffer reading shells
  
  _local_initshells did not reset cp to the beginning of the line buffer for
  every iteration that it called fgets(3), leading to writing past the end of
  line with fairly long /etc/shells or excessively long line lengths. Correct
  this by properly resetting cp.
  
  PR:		192528

Modified:
  stable/11/lib/libc/gen/getusershell.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/lib/libc/gen/getusershell.c
==============================================================================
--- stable/11/lib/libc/gen/getusershell.c	Tue Feb 27 19:02:49 2018	(r330080)
+++ stable/11/lib/libc/gen/getusershell.c	Tue Feb 27 19:24:06 2018	(r330081)
@@ -115,8 +115,8 @@ _local_initshells(void	*rv, void *cb_data, va_list ap)
 	if ((fp = fopen(_PATH_SHELLS, "re")) == NULL)
 		return NS_UNAVAIL;
 
-	cp = line;
-	while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
+	while (fgets(line, MAXPATHLEN + 1, fp) != NULL) {
+		cp = line;
 		while (*cp != '#' && *cp != '/' && *cp != '\0')
 			cp++;
 		if (*cp == '#' || *cp == '\0')
@@ -124,7 +124,7 @@ _local_initshells(void	*rv, void *cb_data, va_list ap)
 		sp = cp;
 		while (!isspace(*cp) && *cp != '#' && *cp != '\0')
 			cp++;
-		*cp++ = '\0';
+		*cp = '\0';
 		sl_add(sl, strdup(sp));
 	}
 	(void)fclose(fp);