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, 17 insertions, 0 deletions

diff --git a/drivers/net/wireless/strip.c b/drivers/net/wireless/strip.c
index ea6a87c19319..698aade79d40 100644
--- a/drivers/net/wireless/strip.c
+++ b/drivers/net/wireless/strip.c
@@ -106,6 +106,7 @@ static const char StripVersion[] = "1.3A-STUART.CHESHIRE";
 #include <linux/serial.h>
 #include <linux/serialP.h>
 #include <linux/rcupdate.h>
+#include <linux/compat.h>
 #include <net/arp.h>
 #include <net/net_namespace.h>
 
@@ -2725,6 +2726,19 @@ static int strip_ioctl(struct tty_struct *tty, struct file *file,
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
+static long strip_compat_ioctl(struct tty_struct *tty, struct file *file,
+		       unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case SIOCGIFNAME:
+	case SIOCSIFHWADDR:
+		return strip_ioctl(tty, file, cmd,
+			(unsigned long)compat_ptr(arg));
+	}
+	return -ENOIOCTLCMD;
+}
+#endif
 
 /************************************************************************/
 /* Initialization							*/
@@ -2736,6 +2750,9 @@ static struct tty_ldisc_ops strip_ldisc = {
 	.open = strip_open,
 	.close = strip_close,
 	.ioctl = strip_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = strip_compat_ioctl,
+#endif
 	.receive_buf = strip_receive_buf,
 	.write_wakeup = strip_write_some_more,
 };