telnetd: check ptsname() for NULL

1 files changed, 16 insertions, 9 deletions

diff --git a/networking/telnetd.c b/networking/telnetd.c
index c6789e19c..da7911fcc 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -188,12 +188,18 @@ getpty(char *line)
 {
         int p;
 #ifdef CONFIG_FEATURE_DEVPTS
-        p = open("/dev/ptmx", 2);
+        p = open("/dev/ptmx", O_RDWR);
         if (p > 0) {
+                const char *name;
                 grantpt(p);
                 unlockpt(p);
-                strcpy(line, ptsname(p));
-                return(p);
+                name = ptsname(p);
+                if (!name) {
+                        bb_perror_msg("ptsname error (is /dev/pts mounted?)");
+                        return -1;
+                }
+                strcpy(line, name);
+                return p;
         }
 #else
         struct stat stb;
@@ -213,7 +219,8 @@ getpty(char *line)
 #ifdef DEBUG
                         fprintf(stderr, "Trying to open device: %s\n", line);
 #endif
-                        if ((p = open(line, O_RDWR | O_NOCTTY)) >= 0) {
+                        p = open(line, O_RDWR | O_NOCTTY);
+                        if (p >= 0) {
                                 line[5] = 't';
                                 return p;
                         }
@@ -387,7 +394,7 @@ telnetd_main(int argc, char **argv)
         openlog(applet_name, 0, LOG_USER);
         logmode = LOGMODE_SYSLOG;
 
-        opt = getopt32(argc, argv, "f:l:" USE_FEATURE_TELNETD_INETD("p:b:"),
+        opt = getopt32(argc, argv, "f:l:" SKIP_FEATURE_TELNETD_INETD("p:b:"),
                         &issuefile, &loginpath
                         SKIP_FEATURE_TELNETD_INETD(, &opt_portnbr, &opt_bindaddr));
         //if (opt & 1) // -f
@@ -435,7 +442,7 @@ telnetd_main(int argc, char **argv)
         maxfd = master_fd;
 #endif /* CONFIG_FEATURE_TELNETD_INETD */
 
-        do {
+        while(1) {
                 struct tsession *ts;
 
                 FD_ZERO(&rdfdset);
@@ -493,8 +500,8 @@ telnetd_main(int argc, char **argv)
                         socklen_t salen;
 
                         salen = sizeof(sa);
-                        if ((fd = accept(master_fd, (struct sockaddr *)&sa,
-                                                &salen)) < 0) {
+                        fd = accept(master_fd, (struct sockaddr *)&sa, &salen);
+                        if (fd < 0) {
                                 continue;
                         } else {
                                 /* Create a new session and link it into
@@ -632,7 +639,7 @@ telnetd_main(int argc, char **argv)
                 }
 #endif /* CONFIG_FEATURE_TELNETD_INETD */
 
-        } while (1);
+        } /* while(1) */
 
         return 0;
 }