[Bluetooth] Fix compat ioctl for BNEP, CMTP and HIDP

There exists no attempt do deal with the fact that a structure with
a uint32_t followed by a pointer is going to be different for 32-bit
and 64-bit userspace. Any 32-bit process trying to use it will be
failing with -EFAULT if it's lucky; suffering from having data dumped
at a random address if it's not.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/net/bluetooth/cmtp/sock.c b/net/bluetooth/cmtp/sock.c
index 10ad7fd91d83..0547edd57734 100644
--- a/net/bluetooth/cmtp/sock.c
+++ b/net/bluetooth/cmtp/sock.c
@@ -34,6 +34,7 @@
 #include <linux/socket.h>
 #include <linux/ioctl.h>
 #include <linux/file.h>
+#include <linux/compat.h>
 #include <net/sock.h>
 
 #include <linux/isdn/capilli.h>
@@ -137,11 +138,43 @@ static int cmtp_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long
         return -EINVAL;
 }
 
+#ifdef CONFIG_COMPAT
+static int cmtp_sock_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+        if (cmd == CMTPGETCONNLIST) {
+                struct cmtp_connlist_req cl;
+                uint32_t uci;
+                int err;
+
+                if (get_user(cl.cnum, (uint32_t __user *) arg) ||
+                                get_user(uci, (u32 __user *) (arg + 4)))
+                        return -EFAULT;
+
+                cl.ci = compat_ptr(uci);
+
+                if (cl.cnum <= 0)
+                        return -EINVAL;
+        
+                err = cmtp_get_connlist(&cl);
+
+                if (!err && put_user(cl.cnum, (uint32_t __user *) arg))
+                        err = -EFAULT;
+
+                return err;
+        }
+
+        return cmtp_sock_ioctl(sock, cmd, arg);
+}
+#endif
+
 static const struct proto_ops cmtp_sock_ops = {
         .family         = PF_BLUETOOTH,
         .owner          = THIS_MODULE,
         .release        = cmtp_sock_release,
         .ioctl          = cmtp_sock_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl   = cmtp_sock_compat_ioctl,
+#endif
         .bind           = sock_no_bind,
         .getname        = sock_no_getname,
         .sendmsg        = sock_no_sendmsg,