[PATCH AUTOSEL 4.18 57/76] mac80211: fix an off-by-one issue in A-MSDU max_subframe computation

[Sasha Levin]

From: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx>

[ Upstream commit 66eb02d839e8495ae6b612e2d09ff599374b80e2 ]

Initialize 'n' to 2 in order to take into account also the first
packet in the estimation of max_subframe limit for a given A-MSDU
since frag_tail pointer is NULL when ieee80211_amsdu_aggregate
routine analyzes the second frame.

Fixes: 6e0456b54545 ("mac80211: add A-MSDU tx support")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 net/mac80211/tx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6ca0865de945..9b3b069e418a 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3174,7 +3174,7 @@ static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata,
 	void *data;
 	bool ret = false;
 	unsigned int orig_len;
-	int n = 1, nfrags, pad = 0;
+	int n = 2, nfrags, pad = 0;
 	u16 hdrlen;
 
 	if (!ieee80211_hw_check(&local->hw, TX_AMSDU))
-- 
2.17.1