From 39fc0591b8b83310bcdf8436bd1f226fc4d6fd23 Mon Sep 17 00:00:00 2001
From: "John W. Linville" <linville@tuxdriver.com>
Date: Tue, 24 Aug 2010 15:27:34 -0400
Subject: ath5k: check return value of ieee80211_get_tx_rate

commit d8e1ba76d619dbc0be8fbeee4e6c683b5c812d3a upstream.

This avoids a NULL pointer dereference as reported here:

	https://bugzilla.redhat.com/show_bug.cgi?id=625889

When the WARN condition is hit in ieee80211_get_tx_rate, it will return
NULL.  So, we need to check the return value and avoid dereferencing it
in that case.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/net/wireless/ath/ath5k/base.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index ab9fe22e4dc..f1e3469f92f 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -1318,6 +1318,10 @@ ath5k_txbuf_setup(struct ath5k_softc *sc, struct ath5k_buf *bf,
 			PCI_DMA_TODEVICE);
 
 	rate = ieee80211_get_tx_rate(sc->hw, info);
+	if (!rate) {
+		ret = -EINVAL;
+		goto err_unmap;
+	}
 
 	if (info->flags & IEEE80211_TX_CTL_NO_ACK)
 		flags |= AR5K_TXDESC_NOACK;
-- 
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