seccomp: don't leak memory when filter install races

[linux-block.git] / kernel / seccomp.c

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 3ee59ce0a323dcad450961a2de31845646f57c1f..bb0dd9ae699a4dd0b252f947de761a36a08194d1 100644 (file)
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1109,13 +1109,12 @@ out:
 }
 
 #ifdef CONFIG_SECCOMP_FILTER
-static int seccomp_notify_release(struct inode *inode, struct file *file)
+static void seccomp_notify_detach(struct seccomp_filter *filter)
 {
-       struct seccomp_filter *filter = file->private_data;
        struct seccomp_knotif *knotif;
 
        if (!filter)
-               return 0;
+               return;
 
        mutex_lock(&filter->notify_lock);
 
@@ -1142,6 +1141,13 @@ static int seccomp_notify_release(struct inode *inode, struct file *file)
        kfree(filter->notif);
        filter->notif = NULL;
        mutex_unlock(&filter->notify_lock);
+}
+
+static int seccomp_notify_release(struct inode *inode, struct file *file)
+{
+       struct seccomp_filter *filter = file->private_data;
+
+       seccomp_notify_detach(filter);
        __put_seccomp_filter(filter);
        return 0;
 }
@@ -1581,6 +1587,7 @@ out_put_fd:
                        listener_f->private_data = NULL;
                        fput(listener_f);
                        put_unused_fd(listener);
+                       seccomp_notify_detach(prepared);
                } else {
                        fd_install(listener, listener_f);
                        ret = listener;