ath9k: range checking issues in htc_hst.c

PATCH In review Dan Carpenter 3 participants 7 messages May 8, 2010 – May 11, 2010 Qualcomm Atheros ATH9K wireless driver

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Dan Carpenter

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2010-05-08 16:22 UTC #0 lore raw

PATCH 2/9 ath9k: range checking issues in htc_hst.c

The original code had ENDPOINT_MAX and HST_ENDPOINT_MAX switched.

Also the first loop was off by one, it started past the end of the array and went down to 1 instead of going down to 0. The test at the end of the loop to see if we exited via a break wasn't right because "tmp_endpoint" is always non-null here.

Signed-off-by Dan Carpenter <[email protected]>

drivers/net/wireless/ath/ath9k/htc_hst.c +5 -5

index 7bf6ce1..0c062d0 100644
@@ -116,7 +116,7 @@ static void htc_process_conn_rsp(struct htc_target *target,
 		max_msglen = be16_to_cpu(svc_rspmsg->max_msg_len);
 		endpoint = &target->endpoint[epid];
 
-		for (tepid = ENDPOINT_MAX; tepid > ENDPOINT0; tepid--) {
+		for (tepid = HST_ENDPOINT_MAX - 1; tepid >= ENDPOINT0; tepid--) {
 			tmp_endpoint = &target->endpoint[tepid];
 			if (tmp_endpoint->service_id == service_id) {
 				tmp_endpoint->service_id = 0;

@@ -124,7 +124,7 @@ static void htc_process_conn_rsp(struct htc_target *target,
 			}
 		}
 
-		if (!tmp_endpoint)
+		if (tepid < ENDPOINT0)
 			return;
 
 		endpoint->service_id = service_id;

@@ -297,7 +297,7 @@ void htc_stop(struct htc_target *target)
 	enum htc_endpoint_id epid;
 	struct htc_endpoint *endpoint;
 
-	for (epid = ENDPOINT0; epid <= ENDPOINT_MAX; epid++) {
+	for (epid = ENDPOINT0; epid < HST_ENDPOINT_MAX; epid++) {
 		endpoint = &target->endpoint[epid];
 		if (endpoint->service_id != 0)
 			target->hif->stop(target->hif_dev, endpoint->ul_pipeid);

@@ -309,7 +309,7 @@ void htc_start(struct htc_target *target)
 	enum htc_endpoint_id epid;
 	struct htc_endpoint *endpoint;
 
-	for (epid = ENDPOINT0; epid <= ENDPOINT_MAX; epid++) {
+	for (epid = ENDPOINT0; epid < HST_ENDPOINT_MAX; epid++) {
 		endpoint = &target->endpoint[epid];
 		if (endpoint->service_id != 0)
 			target->hif->start(target->hif_dev,

@@ -377,7 +377,7 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle,
 	htc_hdr = (struct htc_frame_hdr *) skb->data;
 	epid = htc_hdr->endpoint_id;
 
-	if (epid >= ENDPOINT_MAX) {
+	if (epid >= HST_ENDPOINT_MAX) {
 		if (pipe_id != USB_REG_IN_PIPE)
 			dev_kfree_skb_any(skb);
 		else

Sujith

2010-05-10 04:36 UTC #1 lore raw

PATCH 2/9 ath9k: range checking issues in htc_hst.c

Quoted 1 line · Dan Carpenter

The original code had ENDPOINT_MAX and HST_ENDPOINT_MAX switched.

Hm, no.

Quoted 12 lines

Also the first loop was off by one, it started past the end of the array and went down to 1 instead of going down to 0. The test at the end of the loop to see if we exited via a break wasn't right because "tmp_endpoint" is always non-null here.
Signed-off-by Dan Carpenter <[email protected]>
drivers/net/wireless/ath/ath9k/htc_hst.c +0 -0
index 7bf6ce1..0c062d0 100644

drivers/net/wireless/ath/ath9k/htc_hst.c static void htc_process_conn_rsp(struct htc_target *target, · line 119

Quoted 5 lines

drivers/net/wireless/ath/ath9k/htc_hst.c +1 -1

@@ -116,7 +116,7 @@ static void htc_process_conn_rsp(struct htc_target *target,
 		max_msglen = be16_to_cpu(svc_rspmsg->max_msg_len);
 		endpoint = &target->endpoint[epid];
 
-		for (tepid = ENDPOINT_MAX; tepid > ENDPOINT0; tepid--) {
+		for (tepid = HST_ENDPOINT_MAX - 1; tepid >= ENDPOINT0; tepid--) {

This should be (tepid = (ENDPOINT_MAX - 1); tepid > ENDPOINT0; tepid--), and the NULL check below can be retained.

This is because ENDPOINT0 is reserved.

Quoted 13 lines

drivers/net/wireless/ath/ath9k/htc_hst.c +1 -1

 			tmp_endpoint = &target->endpoint[tepid];
 			if (tmp_endpoint->service_id == service_id) {
 				tmp_endpoint->service_id = 0;

@@ -124,7 +124,7 @@ static void htc_process_conn_rsp(struct htc_target *target,
 			}
 		}
 
-		if (!tmp_endpoint)
+		if (tepid < ENDPOINT0)
 			return;
 
 		endpoint->service_id = service_id;

drivers/net/wireless/ath/ath9k/htc_hst.c void htc_stop(struct htc_target *target) · line 300

Quoted 5 lines

drivers/net/wireless/ath/ath9k/htc_hst.c +1 -1

@@ -297,7 +297,7 @@ void htc_stop(struct htc_target *target)
 	enum htc_endpoint_id epid;
 	struct htc_endpoint *endpoint;
 
-	for (epid = ENDPOINT0; epid <= ENDPOINT_MAX; epid++) {
+	for (epid = ENDPOINT0; epid < HST_ENDPOINT_MAX; epid++) {

ENDPOINT_MAX should be used here, but '<=' should be replaced by '<'.

drivers/net/wireless/ath/ath9k/htc_hst.c void htc_start(struct htc_target *target) · line 313

Quoted 10 lines

drivers/net/wireless/ath/ath9k/htc_hst.c +1 -1

 		endpoint = &target->endpoint[epid];
 		if (endpoint->service_id != 0)
 			target->hif->stop(target->hif_dev, endpoint->ul_pipeid);

@@ -309,7 +309,7 @@ void htc_start(struct htc_target *target)
 	enum htc_endpoint_id epid;
 	struct htc_endpoint *endpoint;
 
-	for (epid = ENDPOINT0; epid <= ENDPOINT_MAX; epid++) {
+	for (epid = ENDPOINT0; epid < HST_ENDPOINT_MAX; epid++) {
 		endpoint = &target->endpoint[epid];

Same as above.

drivers/net/wireless/ath/ath9k/htc_hst.c void ath9k_htc_rx_msg(struct htc_target *htc_handle, · line 383

Quoted 11 lines

drivers/net/wireless/ath/ath9k/htc_hst.c +1 -1

 		if (endpoint->service_id != 0)
 			target->hif->start(target->hif_dev,

@@ -377,7 +377,7 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle,
 	htc_hdr = (struct htc_frame_hdr *) skb->data;
 	epid = htc_hdr->endpoint_id;
 
-	if (epid >= ENDPOINT_MAX) {
+	if (epid >= HST_ENDPOINT_MAX) {
 		if (pipe_id != USB_REG_IN_PIPE)
 			dev_kfree_skb_any(skb);
 		else

The original check was correct ...

Sujith

Dan Carpenter

author

2010-05-10 10:23 UTC #2 lore raw

PATCH 2/9 ath9k: range checking issues in htc_hst.c

Quoted 5 lines · Sujith

Quoted 1 line · Dan Carpenter
The original code had ENDPOINT_MAX and HST_ENDPOINT_MAX switched.
Hm, no.

I'm afraid I don't understand. ENDPOINT_MAX is 22 and HST_ENDPOINT_MAX is 8. The htc_target struct is defined as having 8 endpoints.

drivers/net/wireless/ath/ath9k/htc_hst.h
137 struct htc_target {

   138          void *hif_dev;
   139          struct ath9k_htc_priv *drv_priv;
   140          struct device *dev;
   141          struct ath9k_htc_hif *hif;
   142          struct htc_endpoint endpoint[HST_ENDPOINT_MAX];
                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^

So in the original code:
drivers/net/wireless/ath/ath9k/htc_hst.c
119 for (tepid = ENDPOINT_MAX; tepid > ENDPOINT0; tepid--) {
120 tmp_endpoint = &target->endpoint[tepid];
^^^^^^^^^^^^^^^^^^^^^^^^^

We are past the end of the array here. 22 vs 7.

Perhaps the htc_target struct should be changed to ENDPOINT_MAX?

regards,
dan carpenter

Sujith

2010-05-10 10:50 UTC #3 lore raw

PATCH 2/9 ath9k: range checking issues in htc_hst.c

Quoted 14 lines · Dan Carpenter

I'm afraid I don't understand. ENDPOINT_MAX is 22 and HST_ENDPOINT_MAX is 8. The htc_target struct is defined as having 8 endpoints.
drivers/net/wireless/ath/ath9k/htc_hst.h
   137  struct htc_target {
   138          void *hif_dev;
   139          struct ath9k_htc_priv *drv_priv;
   140          struct device *dev;
   141          struct ath9k_htc_hif *hif;
   142          struct htc_endpoint endpoint[HST_ENDPOINT_MAX];
                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
So in the original code:
drivers/net/wireless/ath/ath9k/htc_hst.c

Quoted 7 lines

   119                  for (tepid = ENDPOINT_MAX; tepid > ENDPOINT0; tepid--) {
   120                          tmp_endpoint = &target->endpoint[tepid];
                                               ^^^^^^^^^^^^^^^^^^^^^^^^^

	We are past the end of the array here.  22 vs 7.

Perhaps the htc_target struct should be changed to ENDPOINT_MAX?

Ah right. That should be fixed.

Sujith

Pavel Roskin

2010-05-10 12:17 UTC #4 lore raw

PATCH 2/9 ath9k: range checking issues in htc_hst.c

Quoted 1 line · Sujith

Ah right. That should be fixed.

I suggest using ARRAY_SIZE(target->endpoint) to be sure.

Signature · 2 lines

Regards,
Pavel Roskin

Sujith.Manoharan at atheros.com

2010-05-11 05:49 UTC #5 lore raw

PATCH 2/9 ath9k: range checking issues in htc_hst.c

In reply to Dan Carpenter

Quoted 6 lines · Dan Carpenter

The original code had ENDPOINT_MAX and HST_ENDPOINT_MAX switched.
Also the first loop was off by one, it started past the end of the array and went down to 1 instead of going down to 0. The test at the end of the loop to see if we exited via a break wasn't right because "tmp_endpoint" is always non-null here.

This is a very good catch and fixes a stack corruption issue. Do you mind if I work upon this patch and send out an updated fix ?

Sujith

Dan Carpenter

author

2010-05-11 09:29 UTC #6 lore raw

PATCH 2/9 ath9k: range checking issues in htc_hst.c

Quoted 8 lines · Sujith.Manoharan at atheros.com

Quoted 6 lines · Dan Carpenter
The original code had ENDPOINT_MAX and HST_ENDPOINT_MAX switched.
Also the first loop was off by one, it started past the end of the array and went down to 1 instead of going down to 0. The test at the end of the loop to see if we exited via a break wasn't right because "tmp_endpoint" is always non-null here.

Quoted 4 lines

This is a very good catch and fixes a stack corruption issue. Do you mind if I work upon this patch and send out an updated fix ?
Sujith

Sorry, I meant to do that yesterday but I was out of it. Yes. Please send the updated fix.

regards,
dan carpenter