kcm: return immediately after copy_from_user() failure

BugLink: http://bugs.launchpad.net/bugs/1688499
[ Upstream commit a80db69e47d764bbcaf2fec54b1f308925e7c490 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index a646f348124095c1bdff2d14a77ea5c0ac892bc1..fecad1098cf839167e588e9b0d08b3a7f9089c92 100644 (file)
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -1685,7 +1685,7 @@ 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);
 
@@ -1695,7 +1695,7 @@ 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);
 
@@ -1706,7 +1706,7 @@ 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);