kcm: return immediately after copy_from_user() failure

There is no reason to continue after a copy_from_user()
failure.

Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index 309062f3debe298c1cf7666f77505f8d353d76d8..31762f76cdb5f2a3ec322135068402be532218ed 100644 (file)
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -1687,7 +1687,7 @@ static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                struct kcm_attach info;
 
                if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
-                       err = -EFAULT;
+                       return -EFAULT;
 
                err = kcm_attach_ioctl(sock, &info);
 
@@ -1697,7 +1697,7 @@ static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                struct kcm_unattach info;
 
                if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
-                       err = -EFAULT;
+                       return -EFAULT;
 
                err = kcm_unattach_ioctl(sock, &info);
 
@@ -1708,7 +1708,7 @@ static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                struct socket *newsock = NULL;
 
                if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
-                       err = -EFAULT;
+                       return -EFAULT;
 
                err = kcm_clone(sock, &info, &newsock);