[gtk: 1/2] pid_get_parent: fix potential leak of kp

[Matthias Clasen <matthiasc src gnome org>]

commit 7d8be1c1ffc31523e2de09d4829169b78dd391e4
Author: Antoine Jacoutot <ajacoutot openbsd org>
Date:   Fri May 17 11:55:16 2019 +0000

    pid_get_parent: fix potential leak of kp

 gtk/gtkmountoperation-x11.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)
---
diff --git a/gtk/gtkmountoperation-x11.c b/gtk/gtkmountoperation-x11.c
index 1b7bff6aa1..268354f31b 100644
--- a/gtk/gtkmountoperation-x11.c
+++ b/gtk/gtkmountoperation-x11.c
@@ -736,25 +736,32 @@ pid_get_command_line (GPid pid)
 static GPid
 pid_get_parent (GPid pid)
 {
-  struct kinfo_proc *kp;
+  struct kinfo_proc *kp = NULL;
   size_t len;
-  GPid ppid;
+  GPid ppid = 0;
+
+  /* fail if trying to get the parent of the init process (no such thing) */
+  if (pid == 1)
+      goto out;
 
   int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, pid,
                 sizeof(struct kinfo_proc), 0 };
 
   if (sysctl (mib, G_N_ELEMENTS (mib), NULL, &len, NULL, 0) == -1)
-      return (-1);
+      goto out;
+
   mib[5] = (len / sizeof(struct kinfo_proc));
 
   kp = g_malloc0 (len);
 
   if (sysctl (mib, G_N_ELEMENTS (mib), kp, &len, NULL, 0) < 0)
-      return -1;
+      goto out;
 
   ppid = kp->p_ppid;
 
-  g_free (kp);
+out:
+  if (kp)
+      g_free (kp);
   return ppid;
 }