=?y?q?=5B=20063/187=5D=20ath9k=3A=20fix=20invalid=20pointer=20access=20in=20the=20tx=20path?=

Greg Kroah-Hartman
2012-07-12T22:39:24Z

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From: Greg KH <gregkh@linuxfoundation.org>

3.4-stable review patch. If anyone has any objections, please let me know.

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

From: Felix Fietkau <nbd@openwrt.org>

commit 80b08a8d8829a58b5db14b1417151094cc28face upstream.

After setup_frame_info has been called, only info->control.rates is still
valid, other control fields have been overwritten by the ath_frame_info
data. Move the access to info->control.vif for checking short preamble
to setup_frame_info before it gets overwritten.

This regression was introduced in commit d47a61aa
"ath9k: Fix multi-VIF BSS handling"

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Reported-by: Thomas Hühn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/ath/ath9k/ath9k.h | 1 +
drivers/net/wireless/ath/ath9k/xmit.c | 29 +++++++++++++++++------------
2 files changed, 18 insertions(+), 12 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -213,6 +213,7 @@ struct ath_frame_info {
enum ath9k_key_type keytype;
u8 keyix;
u8 retries;
+ u8 rtscts_rate;
};

struct ath_buf_state {
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -938,6 +938,7 @@ static void ath_buf_set_rate(struct ath_
struct ieee80211_tx_rate *rates;
const struct ieee80211_rate *rate;
struct ieee80211_hdr *hdr;
+ struct ath_frame_info *fi = get_frame_info(bf->bf_mpdu);
int i;
u8 rix = 0;

@@ -948,18 +949,7 @@ static void ath_buf_set_rate(struct ath_

/* set dur_update_en for l-sig computation except for PS-Poll frames */
info->dur_update = !ieee80211_is_pspoll(hdr->frame_control);
-
- /*
- * We check if Short Preamble is needed for the CTS rate by
- * checking the BSS's global flag.
- * But for the rate series, IEEE80211_TX_RC_USE_SHORT_PREAMBLE is used.
- */
- rate = ieee80211_get_rts_cts_rate(sc->hw, tx_info);
- info->rtscts_rate = rate->hw_value;
-
- if (tx_info->control.vif &&
- tx_info->control.vif->bss_conf.use_short_preamble)
- info->rtscts_rate |= rate->hw_value_short;
+ info->rtscts_rate = fi->rtscts_rate;

for (i = 0; i < 4; i++) {
bool is_40, is_sgi, is_sp;
@@ -1776,10 +1766,22 @@ static void setup_frame_info(struct ieee
struct ieee80211_sta *sta = tx_info->control.sta;
struct ieee80211_key_conf *hw_key = tx_info->control.hw_key;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+ const struct ieee80211_rate *rate;
struct ath_frame_info *fi = get_frame_info(skb);
struct ath_node *an = NULL;
enum ath9k_key_type keytype;
+ bool short_preamble = false;
+
+ /*
+ * We check if Short Preamble is needed for the CTS rate by
+ * checking the BSS's global flag.
+ * But for the rate series, IEEE80211_TX_RC_USE_SHORT_PREAMBLE is used.
+ */
+ if (tx_info->control.vif &&
+ tx_info->control.vif->bss_conf.use_short_preamble)
+ short_preamble = true;

+ rate = ieee80211_get_rts_cts_rate(hw, tx_info);
keytype = ath9k_cmn_get_hw_crypto_keytype(skb);

if (sta)
@@ -1794,6 +1796,9 @@ static void setup_frame_info(struct ieee
fi->keyix = ATH9K_TXKEYIX_INVALID;
fi->keytype = keytype;
fi->framelen = framelen;
+ fi->rtscts_rate = rate->hw_value;
+ if (short_preamble)
+ fi->rtscts_rate |= rate->hw_value_short;
}

u8 ath_txchainmask_reduction(struct ath_softc *sc, u8 chainmask, u32 rate)