[PATCH] ath9k: hif_usb: fix memory leak in ath9k_hif_usb_firmware_cb

Subsystems: atheros ath generic utilities, qualcomm atheros ath9k wireless driver, the rest

STALE1879d

3 messages, 2 authors, 2021-07-27 · open the first message on its own page

[PATCH] ath9k: hif_usb: fix memory leak in ath9k_hif_usb_firmware_cb

From: Dongliang Mu <hidden>
Date: 2021-07-09 08:44:12

The commit 03fb92a432ea ("ath9k: hif_usb: fix race condition between
usb_get_urb() and usb_kill_anchored_urbs()") adds three usb_get_urb
in ath9k_hif_usb_dealloc_tx_urbs and usb_free_urb.

Fix this bug by adding corresponding usb_free_urb in
ath9k_hif_usb_dealloc_tx_urbs other and hif_usb_stop.

Reported-by: syzbot+6692c72009680f7c4eb2@syzkaller.appspotmail.com
Fixes: 03fb92a432ea ("ath9k: hif_usb: fix race condition between usb_get_urb() and usb_kill_anchored_urbs()")
Signed-off-by: Dongliang Mu <redacted>
---
 drivers/net/wireless/ath/ath9k/hif_usb.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 860da13bfb6a..bda91ff3289b 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c

@@ -457,6 +457,7 @@ static void hif_usb_stop(void *hif_handle)
 		usb_kill_urb(tx_buf->urb);
 		list_del(&tx_buf->list);
 		usb_free_urb(tx_buf->urb);
+		usb_free_urb(tx_buf->urb);
 		kfree(tx_buf->buf);
 		kfree(tx_buf);
 		spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);

@@ -779,6 +780,7 @@ static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev)
 		usb_kill_urb(tx_buf->urb);
 		list_del(&tx_buf->list);
 		usb_free_urb(tx_buf->urb);
+		usb_free_urb(tx_buf->urb);
 		kfree(tx_buf->buf);
 		kfree(tx_buf);
 		spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);

@@ -797,6 +799,7 @@ static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev)
 		usb_kill_urb(tx_buf->urb);
 		list_del(&tx_buf->list);
 		usb_free_urb(tx_buf->urb);
+		usb_free_urb(tx_buf->urb);
 		kfree(tx_buf->buf);
 		kfree(tx_buf);
 		spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);

-- 
2.25.1

Re: [PATCH] ath9k: hif_usb: fix memory leak in ath9k_hif_usb_firmware_cb

From: Dongliang Mu <hidden>
Date: 2021-07-23 10:13:30

On Fri, Jul 9, 2021 at 4:44 PM Dongliang Mu [off-list ref] wrote:

The commit 03fb92a432ea ("ath9k: hif_usb: fix race condition between
usb_get_urb() and usb_kill_anchored_urbs()") adds three usb_get_urb
in ath9k_hif_usb_dealloc_tx_urbs and usb_free_urb.

Fix this bug by adding corresponding usb_free_urb in
ath9k_hif_usb_dealloc_tx_urbs other and hif_usb_stop.

Any idea about this patch?

quoted hunk

Reported-by: syzbot+6692c72009680f7c4eb2@syzkaller.appspotmail.com
Fixes: 03fb92a432ea ("ath9k: hif_usb: fix race condition between usb_get_urb() and usb_kill_anchored_urbs()")
Signed-off-by: Dongliang Mu <redacted>
---
 drivers/net/wireless/ath/ath9k/hif_usb.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 860da13bfb6a..bda91ff3289b 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c

@@ -457,6 +457,7 @@ static void hif_usb_stop(void *hif_handle)
                usb_kill_urb(tx_buf->urb);
                list_del(&tx_buf->list);
                usb_free_urb(tx_buf->urb);
+               usb_free_urb(tx_buf->urb);
                kfree(tx_buf->buf);
                kfree(tx_buf);
                spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);

@@ -779,6 +780,7 @@ static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev)
                usb_kill_urb(tx_buf->urb);
                list_del(&tx_buf->list);
                usb_free_urb(tx_buf->urb);
+               usb_free_urb(tx_buf->urb);
                kfree(tx_buf->buf);
                kfree(tx_buf);
                spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);

@@ -797,6 +799,7 @@ static void ath9k_hif_usb_dealloc_tx_urbs(struct hif_device_usb *hif_dev)
                usb_kill_urb(tx_buf->urb);
                list_del(&tx_buf->list);
                usb_free_urb(tx_buf->urb);
+               usb_free_urb(tx_buf->urb);
                kfree(tx_buf->buf);
                kfree(tx_buf);
                spin_lock_irqsave(&hif_dev->tx.tx_lock, flags);
--

2.25.1

Re: [PATCH] ath9k: hif_usb: fix memory leak in ath9k_hif_usb_firmware_cb

From: Julian Calaby <hidden>
Date: 2021-07-27 07:25:01

Hi Dongliang,

(Drive-by review, I know almost nothing about the code in question)

On Fri, Jul 9, 2021 at 6:47 PM Dongliang Mu [off-list ref] wrote:

quoted hunk

The commit 03fb92a432ea ("ath9k: hif_usb: fix race condition between
usb_get_urb() and usb_kill_anchored_urbs()") adds three usb_get_urb
in ath9k_hif_usb_dealloc_tx_urbs and usb_free_urb.

Fix this bug by adding corresponding usb_free_urb in
ath9k_hif_usb_dealloc_tx_urbs other and hif_usb_stop.

Reported-by: syzbot+6692c72009680f7c4eb2@syzkaller.appspotmail.com
Fixes: 03fb92a432ea ("ath9k: hif_usb: fix race condition between usb_get_urb() and usb_kill_anchored_urbs()")
Signed-off-by: Dongliang Mu <redacted>
---
 drivers/net/wireless/ath/ath9k/hif_usb.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 860da13bfb6a..bda91ff3289b 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c

@@ -457,6 +457,7 @@ static void hif_usb_stop(void *hif_handle)
                usb_kill_urb(tx_buf->urb);
                list_del(&tx_buf->list);
                usb_free_urb(tx_buf->urb);
+               usb_free_urb(tx_buf->urb);

Ok, so if I'm reading this correctly, before the first usb_free_urb()
call, we have two references to the urb at tx_buf->urb.

Why?

Isn't the better fix here to detangle why there's more than one
reference to it and resolve it that way? This looks like a hack to fix
something much more fundamentally broken.

Thanks,

-- 
Julian Calaby

Email: julian.calaby@gmail.com
Profile: http://www.google.com/profiles/julian.calaby/

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