From: John W. Linville <linville@tuxdriver.com>
Date: Tue, 24 Aug 2010 19:27:34 +0000 (-0400)
Subject: ath5k: check return value of ieee80211_get_tx_rate
X-Git-Tag: v2.6.34.8~186
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4bc2b2fce7a6de8df10442c73600327b6b999706;p=thirdparty%2Fkernel%2Fstable.git

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: Paul Gortmaker <paul.gortmaker@windriver.com>
---

diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index db8416966670c..61023e96649e3 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -1316,6 +1316,10 @@ 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;