From: Arnd Bergmann <a...@arndb.de>

The bridge driver has an old set of ioctls using the SIOCDEVPRIVATE
namespace that have never worked in compat mode and are explicitly
forbidden already.

Move them over to ndo_siocdevprivate and fix compat mode for these,
because we can.

Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 net/bridge/br_device.c  |  1 +
 net/bridge/br_ioctl.c   | 36 ++++++++++++++++++++++++------------
 net/bridge/br_private.h |  2 ++
 3 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 6f742fee874a..c272fa57110d 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -409,6 +409,7 @@ static const struct net_device_ops br_netdev_ops = {
        .ndo_change_rx_flags     = br_dev_change_rx_flags,
        .ndo_change_mtu          = br_change_mtu,
        .ndo_do_ioctl            = br_dev_ioctl,
+       .ndo_siocdevprivate      = br_dev_siocdevprivate,
 #ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_netpoll_setup       = br_netpoll_setup,
        .ndo_netpoll_cleanup     = br_netpoll_cleanup,
diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
index 2db800fc27ca..7fbfeb735bad 100644
--- a/net/bridge/br_ioctl.c
+++ b/net/bridge/br_ioctl.c
@@ -106,15 +106,31 @@ static int add_del_if(struct net_bridge *br, int ifindex, 
int isadd)
  * This interface is deprecated because it was too difficult
  * to do the translation for 32/64bit ioctl compatibility.
  */
-static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
+int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void 
__user *data, int cmd)
 {
        struct net_bridge *br = netdev_priv(dev);
        struct net_bridge_port *p = NULL;
        unsigned long args[4];
+       void __user *argp;
        int ret = -EOPNOTSUPP;
 
-       if (copy_from_user(args, rq->ifr_data, sizeof(args)))
-               return -EFAULT;
+       if (in_compat_syscall()) {
+               unsigned int cargs[4];
+               if (copy_from_user(cargs, data, sizeof(cargs)))
+                       return -EFAULT;
+
+               args[0] = cargs[0];
+               args[1] = cargs[1];
+               args[2] = cargs[2];
+               args[3] = cargs[3];
+
+               argp = compat_ptr(args[1]);
+       } else {
+               if (copy_from_user(args, data, sizeof(args)))
+                       return -EFAULT;
+
+               argp = (void __user *)args[1];
+       }
 
        switch (args[0]) {
        case BRCTL_ADD_IF:
@@ -171,7 +187,7 @@ static int old_dev_ioctl(struct net_device *dev, struct 
ifreq *rq, int cmd)
                        return -ENOMEM;
 
                get_port_ifindices(br, indices, num);
-               if (copy_to_user((void __user *)args[1], indices, 
num*sizeof(int)))
+               if (copy_to_user(argp, indices, num*sizeof(int)))
                        num =  -EFAULT;
                kfree(indices);
                return num;
@@ -232,7 +248,7 @@ static int old_dev_ioctl(struct net_device *dev, struct 
ifreq *rq, int cmd)
 
                rcu_read_unlock();
 
-               if (copy_to_user((void __user *)args[1], &p, sizeof(p)))
+               if (copy_to_user(argp, &p, sizeof(p)))
                        return -EFAULT;
 
                return 0;
@@ -282,8 +298,7 @@ static int old_dev_ioctl(struct net_device *dev, struct 
ifreq *rq, int cmd)
        }
 
        case BRCTL_GET_FDB_ENTRIES:
-               return get_fdb_entries(br, (void __user *)args[1],
-                                      args[2], args[3]);
+               return get_fdb_entries(br, argp, args[2], args[3]);
        }
 
        if (!ret) {
@@ -320,7 +335,7 @@ static int old_deviceless(struct net *net, void __user 
*uarg)
 
                args[2] = get_bridge_ifindices(net, indices, args[2]);
 
-               ret = copy_to_user((void __user *)args[1], indices, 
args[2]*sizeof(int))
+               ret = copy_to_user(uarg, indices, args[2]*sizeof(int))
                        ? -EFAULT : args[2];
 
                kfree(indices);
@@ -335,7 +350,7 @@ static int old_deviceless(struct net *net, void __user 
*uarg)
                if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
                        return -EPERM;
 
-               if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
+               if (copy_from_user(buf, uarg, IFNAMSIZ))
                        return -EFAULT;
 
                buf[IFNAMSIZ-1] = 0;
@@ -383,9 +398,6 @@ int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, 
int cmd)
        struct net_bridge *br = netdev_priv(dev);
 
        switch (cmd) {
-       case SIOCDEVPRIVATE:
-               return old_dev_ioctl(dev, rq, cmd);
-
        case SIOCBRADDIF:
        case SIOCBRDELIF:
                return add_del_if(br, rq->ifr_ifindex, cmd == SIOCBRADDIF);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 345118e35c42..a788fcdd2adf 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -778,6 +778,8 @@ br_port_get_check_rtnl(const struct net_device *dev)
 
 /* br_ioctl.c */
 int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
+int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq,
+                         void __user *data, int cmd);
 int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd,
                             void __user *arg);
 
-- 
2.27.0

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