Paged RX skb patch broke the defragmentation. We need to read hdr again
after linearization.
It fixes following bug
http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2194
Signed-off-by: Zhu, Yi <[email protected]>
Signed-off-by: Abhijeet Kolekar <[email protected]>
---
v2: Changed hdr reading.
v3: Added more comments.
v4: added ACCESS_ONCE
net/mac80211/rx.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 9a08f2c..af61aeb 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1253,6 +1253,13 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
+ /*
+ * skb_linearize() might change the skb->data and
+ * previously cached variables (in this case, hdr) need to
+ * be refreshed with the new data. Also make sure compiler won't
+ * do any weird assignments.
+ */
+ hdr = (struct ieee80211_hdr *)ACCESS_ONCE(rx->skb->data);
seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
if (frag == 0) {
--
1.6.3.3