svn commit: r305651 - head/usr.sbin/newsyslog

[Ed Schouten]

Author: ed
Date: Fri Sep  9 07:10:50 2016
New Revision: 305651
URL: https://svnweb.freebsd.org/changeset/base/305651

Log:
  Properly patch up dirname()/basename() calls to not clobber ent->log.
  
  It turns out that we had a couple of more calls to dirname()/basename()
  in newsyslog(8) that assume the input isn't clobbered. This is bad,
  because it apparently breaks log rotation now that the new dirname()
  implementation has been merged.
  
  Fix this by first copying the input and then calling
  dirname()/basename(). While there, improve the naming of variables in
  this function a bit.
  
  Reported by:	Ryan Steinmetz, gjb
  Reviewed by:	bdrewery, allanjude
  Differential Revision:	https://reviews.freebsd.org/D7838

Modified:
  head/usr.sbin/newsyslog/newsyslog.c

Modified: head/usr.sbin/newsyslog/newsyslog.c
==============================================================================
--- head/usr.sbin/newsyslog/newsyslog.c	Fri Sep  9 07:00:50 2016	(r305650)
+++ head/usr.sbin/newsyslog/newsyslog.c	Fri Sep  9 07:10:50 2016	(r305651)
@@ -1510,11 +1510,11 @@ validate_old_timelog(int fd, const struc
 static void
 delete_oldest_timelog(const struct conf_entry *ent, const char *archive_dir)
 {
-	char *logfname, *s, *dir, errbuf[80];
+	char *basebuf, *dirbuf, errbuf[80];
+	const char *base, *dir;
 	int dir_fd, i, logcnt, max_logcnt;
 	struct oldlog_entry *oldlogs;
 	struct dirent *dp;
-	const char *cdir;
 	struct tm tm;
 	DIR *dirp;
 
@@ -1522,19 +1522,19 @@ delete_oldest_timelog(const struct conf_
 	max_logcnt = MAX_OLDLOGS;
 	logcnt = 0;
 
-	if (archive_dir != NULL && archive_dir[0] != '\0')
-		cdir = archive_dir;
-	else
-		if ((cdir = dirname(ent->log)) == NULL)
-			err(1, "dirname()");
-	if ((dir = strdup(cdir)) == NULL)
-		err(1, "strdup()");
+	if (archive_dir != NULL && archive_dir[0] != '\0') {
+		dirbuf = NULL;
+		dir = archive_dir;
+	} else {
+		if ((dirbuf = strdup(ent->log)) == NULL)
+			err(1, "strdup()");
+		dir = dirname(dirbuf);
+	}
 
-	if ((s = basename(ent->log)) == NULL)
-		err(1, "basename()");
-	if ((logfname = strdup(s)) == NULL)
+	if ((basebuf = strdup(ent->log)) == NULL)
 		err(1, "strdup()");
-	if (strcmp(logfname, "/") == 0)
+	base = basename(basebuf);
+	if (strcmp(base, "/") == 0)
 		errx(1, "Invalid log filename - became '/'");
 
 	if (verbose > 2)
@@ -1545,7 +1545,7 @@ delete_oldest_timelog(const struct conf_
 		err(1, "Cannot open log directory '%s'", dir);
 	dir_fd = dirfd(dirp);
 	while ((dp = readdir(dirp)) != NULL) {
-		if (validate_old_timelog(dir_fd, dp, logfname, &tm) == 0)
+		if (validate_old_timelog(dir_fd, dp, base, &tm) == 0)
 			continue;
 
 		/*
@@ -1610,8 +1610,8 @@ delete_oldest_timelog(const struct conf_
 		free(oldlogs[i].fname);
 	}
 	free(oldlogs);
-	free(logfname);
-	free(dir);
+	free(dirbuf);
+	free(basebuf);
 }
 
 /*