Fix a pty-freeing error which caused a segfault if you attempted to

[u/mdw/putty] / unix / uxpty.c

diff --git a/unix/uxpty.c b/unix/uxpty.c
index 186ff5a..5ebd050 100644 (file)
--- a/unix/uxpty.c
+++ b/unix/uxpty.c
@@ -270,7 +270,6 @@ static void fatal_sig_handler(int signum)
 {
     putty_signal(signum, SIG_DFL);
     cleanup_utmp();
-    setuid(getuid());
     raise(signum);
 }
 #endif
@@ -412,6 +411,7 @@ void pty_pre_init(void)
 #endif
 
     pty = single_pty = snew(struct pty_tag);
+    pty->conf = NULL;
     bufchain_init(&pty->output_data);
 
     /* set the child signal handler straight away; it needs to be set
@@ -531,11 +531,23 @@ void pty_pre_init(void)
        int gid = getgid(), uid = getuid();
        int setresgid(gid_t, gid_t, gid_t);
        int setresuid(uid_t, uid_t, uid_t);
-       setresgid(gid, gid, gid);
-       setresuid(uid, uid, uid);
+       if (setresgid(gid, gid, gid) < 0) {
+            perror("setresgid");
+            exit(1);
+        }
+       if (setresuid(uid, uid, uid) < 0) {
+            perror("setresuid");
+            exit(1);
+        }
 #else
-       setgid(getgid());
-       setuid(getuid());
+       if (setgid(getgid()) < 0) {
+            perror("setgid");
+            exit(1);
+        }
+       if (setuid(getuid()) < 0) {
+            perror("setuid");
+            exit(1);
+        }
 #endif
     }
 }
@@ -622,6 +634,7 @@ int pty_real_select_result(Pty pty, int event, int status)
        if (close_on_exit == FORCE_OFF ||
            (close_on_exit == AUTO && pty->exit_code != 0)) {
            char message[512];
+            message[0] = '\0';
            if (WIFEXITED(pty->exit_code))
                sprintf(message, "\r\n[pterm: process terminated with exit"
                        " code %d]\r\n", WEXITSTATUS(pty->exit_code));
@@ -713,6 +726,7 @@ static const char *pty_init(void *frontend, void **backend_handle, Conf *conf,
 
     if (single_pty) {
        pty = single_pty;
+        assert(pty->conf == NULL);
     } else {
        pty = snew(struct pty_tag);
        pty->master_fd = pty->slave_fd = -1;
@@ -748,21 +762,23 @@ static const char *pty_init(void *frontend, void **backend_handle, Conf *conf,
      * Stamp utmp (that is, tell the utmp helper process to do so),
      * or not.
      */
-    if (!conf_get_int(conf, CONF_stamp_utmp)) {
-       close(pty_utmp_helper_pipe);   /* just let the child process die */
-       pty_utmp_helper_pipe = -1;
-    } else if (pty_utmp_helper_pipe >= 0) {
-       char *location = get_x_display(pty->frontend);
-       int len = strlen(location)+1, pos = 0;   /* +1 to include NUL */
-       while (pos < len) {
-           int ret = write(pty_utmp_helper_pipe, location+pos, len - pos);
-           if (ret < 0) {
-               perror("pterm: writing to utmp helper process");
-               close(pty_utmp_helper_pipe);   /* arrgh, just give up */
-               pty_utmp_helper_pipe = -1;
-               break;
-           }
-           pos += ret;
+    if (pty_utmp_helper_pipe >= 0) {   /* if it's < 0, we can't anyway */
+        if (!conf_get_int(conf, CONF_stamp_utmp)) {
+            close(pty_utmp_helper_pipe);   /* just let the child process die */
+            pty_utmp_helper_pipe = -1;
+        } else {
+            char *location = get_x_display(pty->frontend);
+            int len = strlen(location)+1, pos = 0;   /* +1 to include NUL */
+            while (pos < len) {
+                int ret = write(pty_utmp_helper_pipe, location+pos, len - pos);
+                if (ret < 0) {
+                    perror("pterm: writing to utmp helper process");
+                    close(pty_utmp_helper_pipe);   /* arrgh, just give up */
+                    pty_utmp_helper_pipe = -1;
+                    break;
+                }
+                pos += ret;
+            }
        }
     }
 #endif
@@ -953,7 +969,17 @@ static void pty_free(void *handle)
     del234(ptys_by_pid, pty);
     del234(ptys_by_fd, pty);
 
-    sfree(pty);
+    conf_free(pty->conf);
+    pty->conf = NULL;
+
+    if (pty == single_pty) {
+        /*
+         * Leave this structure around in case we need to Restart
+         * Session.
+         */
+    } else {
+        sfree(pty);
+    }
 }
 
 static void pty_try_write(Pty pty)