Re: Libertas: Association request to the driver failed

On Tue, 2009-08-11 at 14:24 -0400, John W. Linville wrote:

Comments from the libertas crowd?  This seems a bit long for this
part of the cycle.

Should we just revert the original patch, then reapply it with this
one for 2.6.32?

I'd feel more comfortable with that.  Roel did find a real problem, but
we need to make sure the fix doesn't break stuff since it appears the
rate code is more complicated than we thought.

Dan

John

On Tue, Aug 11, 2009 at 09:02:14AM +0200, Roel Kluin wrote:

quoted

The size of the tmp buffer was too small, causing a regression

rates->rates has an arraysize of 1, so a memcpy with
MAX_RATES (14) was already causing reads out of bounds.

In get_common_rates() the memset/memcpy can be moved upwards.

Signed-off-by: Roel Kluin <redacted>
Tested-by: Daniel Mack <redacted>
---

quoted

Delta patch, please...

Here,

diff --git a/drivers/net/wireless/libertas/assoc.c b/drivers/net/wireless/libertas/assoc.c
index d699737..ba0164a 100644
--- a/drivers/net/wireless/libertas/assoc.c
+++ b/drivers/net/wireless/libertas/assoc.c

@@ -44,8 +44,8 @@ static int get_common_rates(struct lbs_private *priv,
 	u16 *rates_size)
 {
 	u8 *card_rates = lbs_bg_rates;
-	int ret = 0, i, j;
-	u8 tmp[(ARRAY_SIZE(lbs_bg_rates) - 1) * (*rates_size - 1)];
+	int i, j;
+	u8 tmp[MAX_RATES * ARRAY_SIZE(lbs_bg_rates)];
 	size_t tmp_size = 0;
 
 	/* For each rate in card_rates that exists in rate1, copy to tmp */

@@ -62,20 +62,23 @@ static int get_common_rates(struct lbs_private *priv,
 	lbs_deb_hex(LBS_DEB_JOIN, "common rates", tmp, tmp_size);
 	lbs_deb_join("TX data rate 0x%02x\n", priv->cur_rate);
 
+	memset(rates, 0, *rates_size);
+	*rates_size = min_t(u16, tmp_size, *rates_size);
+	memcpy(rates, tmp, *rates_size);
+
 	if (!priv->enablehwauto) {
 		for (i = 0; i < tmp_size; i++) {
 			if (tmp[i] == priv->cur_rate)
-				goto done;
+				break;
+		}
+		if (i == tmp_size) {
+			lbs_pr_alert("Previously set fixed data rate %#x isn't "
+					"compatible with the network.\n",
+					priv->cur_rate);
+			return -1;
 		}
-		lbs_pr_alert("Previously set fixed data rate %#x isn't "
-		       "compatible with the network.\n", priv->cur_rate);
-		ret = -1;
 	}
-done:
-	memset(rates, 0, *rates_size);
-	*rates_size = min_t(int, tmp_size, *rates_size);
-	memcpy(rates, tmp, *rates_size);
-	return ret;
+	return 0;
 }
 
 

@@ -319,8 +322,8 @@ static int lbs_associate(struct lbs_private *priv,
 
 	rates = (struct mrvl_ie_rates_param_set *) pos;
 	rates->header.type = cpu_to_le16(TLV_TYPE_RATES);
-	memcpy(&rates->rates, &bss->rates, MAX_RATES);
 	tmplen = min_t(u16, ARRAY_SIZE(rates->rates), MAX_RATES);
+	memcpy(&rates->rates, &bss->rates, tmplen);
 	if (get_common_rates(priv, rates->rates, &tmplen)) {
 		ret = -1;
 		goto done;