[PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx

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* [PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
@ 2018-11-16 16:19   ` Lorenzo Bianconi
  0 siblings, 0 replies; 6+ messages in thread
From: Lorenzo Bianconi @ 2018-11-16 16:19 UTC (permalink / raw)
  To: kvalo; +Cc: nbd, linux-wireless, netdev

Starting from mac80211 commit adf8ed01e4fd ("mac80211: add an optional
TXQ for other PS-buffered frames") and commit 0eeb2b674f05 ("mac80211:
add an option for station management TXQ") a new per-sta queue has been
introduced for bufferable management frames.
sta->txq[IEEE80211_NUM_TIDS] is initialized just if the driver reports
the following hw flags:
- IEEE80211_HW_STA_MMPDU_TXQ
- IEEE80211_HW_BUFF_MMPDU_TXQ
This can produce a NULL pointer dereference in mt76_stop_tx_queues
since mt76 iterates on all available sta tx queues assuming they are
initialized by mac80211. This issue has been spotted analyzing the code
(it has not triggered any crash yet)

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
This patch is for 4.20
---
 drivers/net/wireless/mediatek/mt76/tx.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 7cbce03aa65b..aa426b838ffa 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -400,7 +400,12 @@ void mt76_stop_tx_queues(struct mt76_dev *dev, struct ieee80211_sta *sta,
 
 	for (i = 0; i < ARRAY_SIZE(sta->txq); i++) {
 		struct ieee80211_txq *txq = sta->txq[i];
-		struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
+		struct mt76_txq *mtxq;
+
+		if (!txq)
+			continue;
+
+		mtxq = (struct mt76_txq *)txq->drv_priv;
 
 		spin_lock_bh(&mtxq->hwq->lock);
 		mtxq->send_bar = mtxq->aggr && send_bar;
-- 
2.19.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
@ 2018-11-16 16:19   ` Lorenzo Bianconi
  0 siblings, 0 replies; 6+ messages in thread
From: Lorenzo Bianconi @ 2018-11-16 16:19 UTC (permalink / raw)
  To: kvalo-sgV2jX0FEOL9JmXXK+q4OQ
  Cc: nbd-Vt+b4OUoWG0, linux-wireless-u79uwXL29TY76Z2rM5mHXA,
	netdev-u79uwXL29TY76Z2rM5mHXA

Starting from mac80211 commit adf8ed01e4fd ("mac80211: add an optional
TXQ for other PS-buffered frames") and commit 0eeb2b674f05 ("mac80211:
add an option for station management TXQ") a new per-sta queue has been
introduced for bufferable management frames.
sta->txq[IEEE80211_NUM_TIDS] is initialized just if the driver reports
the following hw flags:
- IEEE80211_HW_STA_MMPDU_TXQ
- IEEE80211_HW_BUFF_MMPDU_TXQ
This can produce a NULL pointer dereference in mt76_stop_tx_queues
since mt76 iterates on all available sta tx queues assuming they are
initialized by mac80211. This issue has been spotted analyzing the code
(it has not triggered any crash yet)

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
This patch is for 4.20
---
 drivers/net/wireless/mediatek/mt76/tx.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 7cbce03aa65b..aa426b838ffa 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -400,7 +400,12 @@ void mt76_stop_tx_queues(struct mt76_dev *dev, struct ieee80211_sta *sta,
 
 	for (i = 0; i < ARRAY_SIZE(sta->txq); i++) {
 		struct ieee80211_txq *txq = sta->txq[i];
-		struct mt76_txq *mtxq = (struct mt76_txq *) txq->drv_priv;
+		struct mt76_txq *mtxq;
+
+		if (!txq)
+			continue;
+
+		mtxq = (struct mt76_txq *)txq->drv_priv;
 
 		spin_lock_bh(&mtxq->hwq->lock);
 		mtxq->send_bar = mtxq->aggr && send_bar;
-- 
2.19.1

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
  2018-11-16 16:19   ` Lorenzo Bianconi
  (?)
@ 2018-11-17 11:13   ` Kalle Valo
  2018-11-17 17:46     ` Lorenzo Bianconi
  -1 siblings, 1 reply; 6+ messages in thread
From: Kalle Valo @ 2018-11-17 11:13 UTC (permalink / raw)
  To: Lorenzo Bianconi; +Cc: nbd, linux-wireless, netdev

Lorenzo Bianconi <lorenzo.bianconi@redhat.com> writes:

> Starting from mac80211 commit adf8ed01e4fd ("mac80211: add an optional
> TXQ for other PS-buffered frames") and commit 0eeb2b674f05 ("mac80211:
> add an option for station management TXQ") a new per-sta queue has been
> introduced for bufferable management frames.
> sta->txq[IEEE80211_NUM_TIDS] is initialized just if the driver reports
> the following hw flags:
> - IEEE80211_HW_STA_MMPDU_TXQ
> - IEEE80211_HW_BUFF_MMPDU_TXQ
> This can produce a NULL pointer dereference in mt76_stop_tx_queues
> since mt76 iterates on all available sta tx queues assuming they are
> initialized by mac80211. This issue has been spotted analyzing the code
> (it has not triggered any crash yet)
>
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

A very good commit log, thanks for that!

> This patch is for 4.20

Ok, I'll wait for review comments and then queue this for 4.20.

BTW, it would make my patch sorting easier if you could add a release
label in the subject:

[PATCH 4.20] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues

More info:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#tree_labels

-- 
Kalle Valo

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
  2018-11-17 11:13   ` Kalle Valo
@ 2018-11-17 17:46     ` Lorenzo Bianconi
  0 siblings, 0 replies; 6+ messages in thread
From: Lorenzo Bianconi @ 2018-11-17 17:46 UTC (permalink / raw)
  To: Kalle Valo; +Cc: Felix Fietkau, linux-wireless, Network Development

> A very good commit log, thanks for that!
>
> > This patch is for 4.20
>
> Ok, I'll wait for review comments and then queue this for 4.20.
>
> BTW, it would make my patch sorting easier if you could add a release
> label in the subject:
>
> [PATCH 4.20] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
>
> More info:
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#tree_labels

Ack, will do next time :)

Regards,
Lorenzo

>
> --
> Kalle Valo

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
@ 2018-12-13 14:20     ` Kalle Valo
  0 siblings, 0 replies; 6+ messages in thread
From: Kalle Valo @ 2018-12-13 14:20 UTC (permalink / raw)
  To: Lorenzo Bianconi; +Cc: nbd, linux-wireless, netdev

Lorenzo Bianconi <lorenzo.bianconi@redhat.com> wrote:

> Starting from mac80211 commit adf8ed01e4fd ("mac80211: add an optional
> TXQ for other PS-buffered frames") and commit 0eeb2b674f05 ("mac80211:
> add an option for station management TXQ") a new per-sta queue has been
> introduced for bufferable management frames.
> sta->txq[IEEE80211_NUM_TIDS] is initialized just if the driver reports
> the following hw flags:
> - IEEE80211_HW_STA_MMPDU_TXQ
> - IEEE80211_HW_BUFF_MMPDU_TXQ
> This can produce a NULL pointer dereference in mt76_stop_tx_queues
> since mt76 iterates on all available sta tx queues assuming they are
> initialized by mac80211. This issue has been spotted analyzing the code
> (it has not triggered any crash yet)
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

Patch applied to wireless-drivers.git, thanks.

7c250f4612ae mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues

-- 
https://patchwork.kernel.org/patch/10686507/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
@ 2018-12-13 14:20     ` Kalle Valo
  0 siblings, 0 replies; 6+ messages in thread
From: Kalle Valo @ 2018-12-13 14:20 UTC (permalink / raw)
  To: Lorenzo Bianconi
  Cc: nbd-Vt+b4OUoWG0, linux-wireless-u79uwXL29TY76Z2rM5mHXA,
	netdev-u79uwXL29TY76Z2rM5mHXA

Lorenzo Bianconi <lorenzo.bianconi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:

> Starting from mac80211 commit adf8ed01e4fd ("mac80211: add an optional
> TXQ for other PS-buffered frames") and commit 0eeb2b674f05 ("mac80211:
> add an option for station management TXQ") a new per-sta queue has been
> introduced for bufferable management frames.
> sta->txq[IEEE80211_NUM_TIDS] is initialized just if the driver reports
> the following hw flags:
> - IEEE80211_HW_STA_MMPDU_TXQ
> - IEEE80211_HW_BUFF_MMPDU_TXQ
> This can produce a NULL pointer dereference in mt76_stop_tx_queues
> since mt76 iterates on all available sta tx queues assuming they are
> initialized by mac80211. This issue has been spotted analyzing the code
> (it has not triggered any crash yet)
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

Patch applied to wireless-drivers.git, thanks.

7c250f4612ae mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues

-- 
https://patchwork.kernel.org/patch/10686507/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2018-12-13 14:20 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
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2018-11-16 16:19 ` [PATCH] mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues Lorenzo Bianconi
2018-11-16 16:19   ` Lorenzo Bianconi
2018-11-17 11:13   ` Kalle Valo
2018-11-17 17:46     ` Lorenzo Bianconi
2018-12-13 14:20   ` Kalle Valo
2018-12-13 14:20     ` Kalle Valo

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