tree ac6e4d45ccfd7a2f2a158d5292366d221445e02c
parent 3c4eef31670361212d4f762c9420fa9a4ff160c0
author Johannes Berg <johannes.berg@intel.com> 1483352369 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1484217547 +0100

mac80211: initialize fast-xmit 'info' later

commit 35f432a03e41d3bf08c51ede917f94e2288fbe8c upstream.

In ieee80211_xmit_fast(), 'info' is initialized to point to the skb
that's passed in, but that skb may later be replaced by a clone (if
it was shared), leading to an invalid pointer.

This can lead to use-after-free and also later crashes since the
real SKB's info->hw_queue doesn't get initialized properly.

Fix this by assigning info only later, when it's needed, after the
skb replacement (may have) happened.

Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>