appletalk: handle SIOCATALKDIFADDR compat ioctl

We must not have a compat ioctl handler for SIOCATALKDIFADDR
in common code, because the same number is used in other protocols
with different data structures.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 4b0ce2e2b46e..7cd08b45c52b 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1811,12 +1811,14 @@ static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 {
         /*
-         * All Appletalk ioctls except SIOCATALKDIFADDR are standard.  And
-         * SIOCATALKDIFADDR is handled by upper layer as well, so there is
-         * nothing to do.  Eventually SIOCATALKDIFADDR should be moved
-         * here so there is no generic SIOCPROTOPRIVATE translation in the
-         * system.
+         * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
+         * cannot handle it in common code. The data we access if ifreq
+         * here is compatible, so we can simply call the native
+         * handler.
          */
+        if (cmd == SIOCATALKDIFADDR)
+                return atalk_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
+
         return -ENOIOCTLCMD;
 }
 #endif