mac80211: Fix panic on fragmentation with power saving

It was possible to hit a kernel panic on NULL pointer dereference in
dev_queue_xmit() when sending power save buffered frames to a STA that
woke up from sleep. This happened when the buffered frame was requeued
for transmission in ap_sta_ps_end(). In order to avoid the panic, copy
the skb->dev and skb->iif values from the first fragment to all other
fragments.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 94de5033f0b6..37e3d5ef7e3f 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -752,6 +752,8 @@ ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
                 skb_copy_queue_mapping(frag, first);
 
                 frag->do_not_encrypt = first->do_not_encrypt;
+                frag->dev = first->dev;
+                frag->iif = first->iif;
 
                 pos += copylen;
                 left -= copylen;