Return-path: Received: from swan.laptop.org ([18.85.2.166]:57590 "EHLO swan.laptop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753528Ab3FNT3L (ORCPT ); Fri, 14 Jun 2013 15:29:11 -0400 From: Daniel Drake To: linville@tuxdriver.com, bzhao@marvell.com Cc: linux-wireless@vger.kernel.org Subject: [PATCH] mwifiex: fix memory corruption when unsetting multicast list Message-Id: <20130614192424.9463CFAAC8@dev.laptop.org> (sfid-20130614_212914_879050_095BB740) Date: Fri, 14 Jun 2013 15:24:24 -0400 (EDT) Sender: linux-wireless-owner@vger.kernel.org List-ID: When trying to unset a previously-set multicast list (i.e. the new list has 0 entries), mwifiex_set_multicast_list() was calling down to mwifiex_request_set_multicast_list() while leaving mcast_list.num_multicast_addr as an uninitialized value. We were arriving at mwifiex_cmd_mac_multicast_adr() which would then proceed to do an often huge memcpy of mcast_list.num_multicast_addr*ETH_ALEN bytes, causing memory corruption and hard to debug crashes. Fix this by setting mcast_list.num_multicast_addr to 0 when no multicast list is provided. Similarly, fix up the logic in mwifiex_request_set_multicast_list() to unset the multicast list that was previously sent to the hardware in such cases. Signed-off-by: Daniel Drake --- drivers/net/wireless/mwifiex/main.c | 5 ++--- drivers/net/wireless/mwifiex/sta_ioctl.c | 18 ++++++++---------- 2 files changed, 10 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/mwifiex/main.c b/drivers/net/wireless/mwifiex/main.c index 2eb88ea..4f5c37a 100644 --- a/drivers/net/wireless/mwifiex/main.c +++ b/drivers/net/wireless/mwifiex/main.c @@ -573,9 +573,8 @@ static void mwifiex_set_multicast_list(struct net_device *dev) mcast_list.mode = MWIFIEX_ALL_MULTI_MODE; } else { mcast_list.mode = MWIFIEX_MULTICAST_MODE; - if (netdev_mc_count(dev)) - mcast_list.num_multicast_addr = - mwifiex_copy_mcast_addr(&mcast_list, dev); + mcast_list.num_multicast_addr = + mwifiex_copy_mcast_addr(&mcast_list, dev); } mwifiex_request_set_multicast_list(priv, &mcast_list); } diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c index 1a8a19d..23aa910 100644 --- a/drivers/net/wireless/mwifiex/sta_ioctl.c +++ b/drivers/net/wireless/mwifiex/sta_ioctl.c @@ -104,16 +104,14 @@ int mwifiex_request_set_multicast_list(struct mwifiex_private *priv, } else { priv->curr_pkt_filter &= ~HostCmd_ACT_MAC_ALL_MULTICAST_ENABLE; - if (mcast_list->num_multicast_addr) { - dev_dbg(priv->adapter->dev, - "info: Set multicast list=%d\n", - mcast_list->num_multicast_addr); - /* Send multicast addresses to firmware */ - ret = mwifiex_send_cmd_async(priv, - HostCmd_CMD_MAC_MULTICAST_ADR, - HostCmd_ACT_GEN_SET, 0, - mcast_list); - } + dev_dbg(priv->adapter->dev, + "info: Set multicast list=%d\n", + mcast_list->num_multicast_addr); + /* Send multicast addresses to firmware */ + ret = mwifiex_send_cmd_async(priv, + HostCmd_CMD_MAC_MULTICAST_ADR, + HostCmd_ACT_GEN_SET, 0, + mcast_list); } } dev_dbg(priv->adapter->dev, -- 1.8.1.4