drivers/net/eql.c: prevent reading uninitialized stack memory

commit 44467187dc22fdd33a1a06ea0ba86ce20be3fe3c upstream.

Fixed formatting (tabs and line breaks).

The EQL_GETMASTRCFG device ioctl allows unprivileged users to read 16
bytes of uninitialized stack memory, because the "master_name" member of
the master_config_t struct declared on the stack in eql_g_master_cfg()
is not altered or zeroed before being copied back to the user.  This
patch takes care of it.

Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/eql.c b/drivers/net/eql.c
index b34a2ddeef4c810b37dca41faad2ed4cc12955b9..a8b982d736f22ff1ce4bb7478839ab7ea4a92cb4 100644 (file)
--- a/drivers/net/eql.c
+++ b/drivers/net/eql.c
@@ -555,6 +555,8 @@ static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
        equalizer_t *eql;
        master_config_t mc;
 
+       memset(&mc, 0, sizeof(master_config_t));
+
        if (eql_is_master(dev)) {
                eql = netdev_priv(dev);
                mc.max_slaves = eql->max_slaves;