net, compat_ioctl: handle socket ioctl abuses in tty drivers

Slip and a few other drivers use the same ioctl numbers on
tty devices that are normally meant for sockets. This causes
problems with our compat_ioctl handling that tries to convert
the data structures in a different format.

Fortunately, these five drivers all use 32 bit compatible
data structures in the ioctl numbers, so we can just add
a trivial compat_ioctl conversion function to each of them.

SIOCSIFENCAP and SIOCGIFENCAP do not need to live in
fs/compat_ioctl.c after this any more, and they are not
used on any sockets.

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

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/net/slip.c b/drivers/net/slip.c
index e17c535..ccfe459 100644
--- a/drivers/net/slip.c
+++ b/drivers/net/slip.c
@@ -79,6 +79,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/if_arp.h>
 #include <linux/if_slip.h>
+#include <linux/compat.h>
 #include <linux/delay.h>
 #include <linux/init.h>
 #include "slip.h"
@@ -1168,6 +1169,27 @@ static int slip_ioctl(struct tty_struct *tty, struct file *file,
 	}
 }
 
+#ifdef CONFIG_COMPAT
+static long slip_compat_ioctl(struct tty_struct *tty, struct file *file,
+					unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case SIOCGIFNAME:
+	case SIOCGIFENCAP:
+	case SIOCSIFENCAP:
+	case SIOCSIFHWADDR:
+	case SIOCSKEEPALIVE:
+	case SIOCGKEEPALIVE:
+	case SIOCSOUTFILL:
+	case SIOCGOUTFILL:
+		return slip_ioctl(tty, file, cmd,
+				  (unsigned long)compat_ptr(arg));
+	}
+
+	return -ENOIOCTLCMD;
+}
+#endif
+
 /* VSV changes start here */
 #ifdef CONFIG_SLIP_SMART
 /* function do_ioctl called from net/core/dev.c
@@ -1260,6 +1282,9 @@ static struct tty_ldisc_ops sl_ldisc = {
 	.close	 	= slip_close,
 	.hangup	 	= slip_hangup,
 	.ioctl		= slip_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= slip_compat_ioctl,
+#endif
 	.receive_buf	= slip_receive_buf,
 	.write_wakeup	= slip_write_wakeup,
 };