Set f_file to -1/F_UNUSED when after closing when possible

This will help ensure we don't trash file descriptors that get used later on
in the daemon

Found via internal Coverity scan

MFC after: 2 weeks
Discussed with: cem, ed, markj
Differential Revision: https://reviews.freebsd.org/D3081
Submitted by: Miles Ohlrich <miles.ohlrich@isilon.com>
Sponsored by: EMC / Isilon Storage Division

1 files changed, 20 insertions, 8 deletions

diff --git a/usr.sbin/syslogd/syslogd.c b/usr.sbin/syslogd/syslogd.c
index ff3e524..fa55e9d 100644
--- a/usr.sbin/syslogd/syslogd.c
+++ b/usr.sbin/syslogd/syslogd.c
@@ -349,6 +349,18 @@ static int	waitdaemon(int, int, int);
 static void	timedout(int);
 static void	increase_rcvbuf(int);
 
+static void
+close_filed(struct filed *f)
+{
+
+	if (f == NULL || f->f_file == -1)
+		return;
+
+	(void)close(f->f_file);
+	f->f_file = -1;
+	f->f_type = F_UNUSED;
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -1024,7 +1036,8 @@ logmsg(int pri, const char *msg, const char *from, int flags)
 			(void)strlcpy(f->f_lasttime, timestamp,
 				sizeof(f->f_lasttime));
 			fprintlog(f, flags, msg);
-			(void)close(f->f_file);
+			close(f->f_file);
+			f->f_file = -1;
 		}
 		(void)sigsetmask(omask);
 		return;
@@ -1313,8 +1326,7 @@ fprintlog(struct filed *f, int flags, const char *msg)
 			 */
 			if (errno != ENOSPC) {
 				int e = errno;
-				(void)close(f->f_file);
-				f->f_type = F_UNUSED;
+				close_filed(f);
 				errno = e;
 				logerror(f->f_un.f_fname);
 			}
@@ -1338,7 +1350,7 @@ fprintlog(struct filed *f, int flags, const char *msg)
 		}
 		if (writev(f->f_file, iov, IOV_SIZE) < 0) {
 			int e = errno;
-			(void)close(f->f_file);
+			close_filed(f);
 			if (f->f_un.f_pipe.f_pid > 0)
 				deadq_enter(f->f_un.f_pipe.f_pid,
 					    f->f_un.f_pipe.f_pname);
@@ -1446,7 +1458,7 @@ reapchild(int signo __unused)
 		for (f = Files; f; f = f->f_next)
 			if (f->f_type == F_PIPE &&
 			    f->f_un.f_pipe.f_pid == pid) {
-				(void)close(f->f_file);
+				close_filed(f);
 				f->f_un.f_pipe.f_pid = 0;
 				log_deadchild(pid, status,
 					      f->f_un.f_pipe.f_pname);
@@ -1550,7 +1562,7 @@ die(int signo)
 		if (f->f_prevcount)
 			fprintlog(f, 0, (char *)NULL);
 		if (f->f_type == F_PIPE && f->f_un.f_pipe.f_pid > 0) {
-			(void)close(f->f_file);
+			close_filed(f);
 			f->f_un.f_pipe.f_pid = 0;
 		}
 	}
@@ -1634,11 +1646,11 @@ init(int signo)
 		case F_FORW:
 		case F_CONSOLE:
 		case F_TTY:
-			(void)close(f->f_file);
+			close_filed(f);
 			break;
 		case F_PIPE:
 			if (f->f_un.f_pipe.f_pid > 0) {
-				(void)close(f->f_file);
+				close_filed(f);
 				deadq_enter(f->f_un.f_pipe.f_pid,
 					    f->f_un.f_pipe.f_pname);
 			}