fcntl: return -EFAULT if copy_to_user fails

copy_to_user() returns the number of bytes remaining, but we want to
return -EFAULT.
	ret = fcntl(fd, F_SETOWN_EX, NULL);
With the original code ret would be 8 here.

V2: Takuya Yoshikawa pointed out a similar issue in f_getown_ex()

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/fcntl.c b/fs/fcntl.c
index f74d270ba155..51e11bf5708f 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -274,7 +274,7 @@ static int f_setown_ex(struct file *filp, unsigned long arg)
 
         ret = copy_from_user(&owner, owner_p, sizeof(owner));
         if (ret)
-                return ret;
+                return -EFAULT;
 
         switch (owner.type) {
         case F_OWNER_TID:
@@ -332,8 +332,11 @@ static int f_getown_ex(struct file *filp, unsigned long arg)
         }
         read_unlock(&filp->f_owner.lock);
 
-        if (!ret)
+        if (!ret) {
                 ret = copy_to_user(owner_p, &owner, sizeof(owner));
+                if (ret)
+                        ret = -EFAULT;
+        }
         return ret;
 }