From 09bdb65005515c97b29e0792bc6e5598d9e4035f Mon Sep 17 00:00:00 2001
From: Douglas Anderson <dianders@chromium.org>
Date: Fri, 12 May 2017 09:42:01 -0700
Subject: [PATCH] mwifiex: Add locking to mwifiex_11n_delba
Git-commit: 09bdb65005515c97b29e0792bc6e5598d9e4035f
Patch-mainline: v4.13-rc1
References: FATE#326294

The mwifiex_11n_delba() function walked the rx_reorder_tbl_ptr without
holding the lock, which was an obvious violation.

Grab the lock.

Note: we hold the lock while calling mwifiex_send_delba().  There's also
several callers in 11n_rxreorder.c that hold the lock and the comments
in the struct sound just like very other list/lock pair -- as if the
lock should definitely be help for all operations like this.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/marvell/mwifiex/11n.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/11n.c b/drivers/net/wireless/marvell/mwifiex/11n.c
index c75b6abf16a0..16c77c27f1b6 100644
--- a/drivers/net/wireless/marvell/mwifiex/11n.c
+++ b/drivers/net/wireless/marvell/mwifiex/11n.c
@@ -653,11 +653,13 @@ int mwifiex_send_delba(struct mwifiex_private *priv, int tid, u8 *peer_mac,
 void mwifiex_11n_delba(struct mwifiex_private *priv, int tid)
 {
 	struct mwifiex_rx_reorder_tbl *rx_reor_tbl_ptr;
+	unsigned long flags;
 
+	spin_lock_irqsave(&priv->rx_reorder_tbl_lock, flags);
 	if (list_empty(&priv->rx_reorder_tbl_ptr)) {
 		dev_dbg(priv->adapter->dev,
 			"mwifiex_11n_delba: rx_reorder_tbl_ptr empty\n");
-		return;
+		goto exit;
 	}
 
 	list_for_each_entry(rx_reor_tbl_ptr, &priv->rx_reorder_tbl_ptr, list) {
@@ -666,9 +668,11 @@ void mwifiex_11n_delba(struct mwifiex_private *priv, int tid)
 				"Send delba to tid=%d, %pM\n",
 				tid, rx_reor_tbl_ptr->ta);
 			mwifiex_send_delba(priv, tid, rx_reor_tbl_ptr->ta, 0);
-			return;
+			goto exit;
 		}
 	}
+exit:
+	spin_unlock_irqrestore(&priv->rx_reorder_tbl_lock, flags);
 }
 
 /*
-- 
2.19.2