[096/129] ath5k: check return value of ieee80211_get_tx_rate

From: Greg KH
Date: Sat Sep 18 2010 - 15:22:48 EST


2.6.35-stable review patch. If anyone has any objections, please let us know.

------------------

From: John W. Linville <linville@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Acked-by: Bob Copeland <me@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/net/wireless/ath/ath5k/base.c | 4 ++++
1 file changed, 4 insertions(+)

--- 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
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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