mwifiex: fix memory corruption when unsetting multicast list

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 <dsd@laptop.org>
Acked-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Daniel Drake
2013-06-14 15:24:24 -04:00
committed by John W. Linville
parent 3c68ef5b22
commit 6390d88529
2 changed files with 10 additions and 13 deletions

View File

@@ -669,9 +669,8 @@ 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);
}