--- /dev/null
+From 81c044fc3bdc5b7be967cd3682528ea94b58c06a Mon Sep 17 00:00:00 2001
+From: Felix Fietkau <nbd@nbd.name>
+Date: Mon, 13 Jan 2020 19:21:07 +0100
+Subject: cfg80211: fix page refcount issue in A-MSDU decap
+
+From: Felix Fietkau <nbd@nbd.name>
+
+commit 81c044fc3bdc5b7be967cd3682528ea94b58c06a upstream.
+
+The fragments attached to a skb can be part of a compound page. In that case,
+page_ref_inc will increment the refcount for the wrong page. Fix this by
+using get_page instead, which calls page_ref_inc on the compound head and
+also checks for overflow.
+
+Fixes: 2b67f944f88c ("cfg80211: reuse existing page fragments in A-MSDU rx")
+Cc: stable@vger.kernel.org
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+Link: https://lore.kernel.org/r/20200113182107.20461-1-nbd@nbd.name
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ net/wireless/util.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/net/wireless/util.c
++++ b/net/wireless/util.c
+@@ -652,7 +652,7 @@ __frame_add_frag(struct sk_buff *skb, st
+ struct skb_shared_info *sh = skb_shinfo(skb);
+ int page_offset;
+
+- page_ref_inc(page);
++ get_page(page);
+ page_offset = ptr - page_address(page);
+ skb_add_rx_frag(skb, sh->nr_frags, page, page_offset, len, size);
+ }