From: Dan Rosenberg <drosenberg@vsecurity.com>
Date: Wed, 15 Sep 2010 11:43:04 +0000 (+0000)
Subject: drivers/net/eql.c: prevent reading uninitialized stack memory
X-Git-Tag: firefly_0821_release~10186^2~911
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ab5fc422d50d6e43faed1d757be1deb2ba2200e0;p=firefly-linux-kernel-4.4.55.git

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: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/net/eql.c b/drivers/net/eql.c
index f5b96cadeb25..fd57fb421e91 100644
--- a/drivers/net/eql.c
+++ b/drivers/net/eql.c
@@ -554,6 +554,8 @@ 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;