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Patch "cfg80211: fix proto in ieee80211_data_to_8023 for frames without LLC header" has been added to the 4.6-stable tree

PATCH [email protected] 1 participant 1 message Jul 11, 2016

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Stable branch 802.11 (including cfg80211/NL80211)
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This is a note to let you know that I've just added the patch titled

cfg80211: fix proto in ieee80211_data_to_8023 for frames without LLC header

to the 4.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     cfg80211-fix-proto-in-ieee80211_data_to_8023-for-frames-without-llc-header.patch

and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From c041778c966c92c964033f1cdfee60a9f2b5e465 Mon Sep 17 00:00:00 2001

From: Felix Fietkau <[email protected]>
Date: Wed, 29 Jun 2016 10:36:39 +0200
Subject: cfg80211: fix proto in ieee80211_data_to_8023 for frames without LLC header

From: Felix Fietkau <[email protected]>

commit c041778c966c92c964033f1cdfee60a9f2b5e465 upstream.

The PDU length of incoming LLC frames is set to the total skb payload size in __ieee80211_data_to_8023() of net/wireless/util.c which incorrectly includes the length of the IEEE 802.11 header.

The resulting LLC frame header has a too large PDU length, causing the llc_fixup_skb() function of net/llc/llc_input.c to reject the incoming skb, effectively breaking STP.

Solve the problem by properly substracting the IEEE 802.11 frame header size from the PDU length, allowing the LLC processor to pick up the incoming control messages.

Special thanks to Gerry Rozema for tracking down the regression and proposing a suitable patch.

Fixes 2d1c304cb2d5 ("cfg80211: add function for 802.3 conversion with separate output buffer")
Reported-by Gerry Rozema <[email protected]>
Signed-off-by Felix Fietkau <[email protected]>
Signed-off-by Johannes Berg <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 net/wireless/util.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
net/wireless/util.c +1 -1
@@ -509,7 +509,7 @@ static int __ieee80211_data_to_8023(stru
 		 * replace EtherType */
 		hdrlen += ETH_ALEN + 2;
 	else
-		tmp.h_proto = htons(skb->len);
+		tmp.h_proto = htons(skb->len - hdrlen);
 
 	pskb_pull(skb, hdrlen);

Patches currently in stable-queue which might be from [email protected] are

queue-4.6/cfg80211-fix-proto-in-ieee80211_data_to_8023-for-frames-without-llc-header.patch queue-4.6/mac80211-fix-fast_tx-header-alignment.patch