[Linux-kernel-mentees] [PATCH v5] bluetooth: hci_h5: fix memory leak in h5_close

[Linux-kernel-mentees] [PATCH v5] bluetooth: hci_h5: fix memory leak in h5_close

[Anant Thazhemadam]

When h5_close() is called, h5 is directly freed when !hu->serdev.
However, h5->rx_skb is not freed, which causes a memory leak.

Freeing h5->rx_skb and setting it to NULL, fixes this memory leak.

Fixes: ce945552fde4 ("Bluetooth: hci_h5: Add support for serdev enumerated devices")
Reported-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
Tested-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
---
Changes in v5:
	* Set h5->rx_skb = NULL unconditionally - to improve code
	  readability
	* Update commit message accordingly

Changes in v4:
	* Free h5->rx_skb even when hu->serdev
	(Suggested by Hans de Goede <hdegoede@redhat.com>)
	* If hu->serdev, then assign h5->rx_skb = NULL

Changes in v3:
	* Free h5->rx_skb when !hu->serdev, and fix the memory leak
	* Do not incorrectly and unnecessarily call serdev_device_close()

Changes in v2:
	* Fixed the Fixes tag


 drivers/bluetooth/hci_h5.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index e41854e0d79a..0ef253136b06 100644
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -245,6 +245,9 @@ static int h5_close(struct hci_uart *hu)
 	skb_queue_purge(&h5->rel);
 	skb_queue_purge(&h5->unrel);
 
+	kfree_skb(h5->rx_skb);
+	h5->rx_skb = NULL;
+
 	if (h5->vnd && h5->vnd->close)
 		h5->vnd->close(h5);
 
-- 
2.25.1

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Re: [Linux-kernel-mentees] [PATCH v5] bluetooth: hci_h5: fix memory leak in h5_close

[Hans de Goede]

Hi,

On 10/16/20 3:14 PM, Anant Thazhemadam wrote:
> When h5_close() is called, h5 is directly freed when !hu->serdev.
> However, h5->rx_skb is not freed, which causes a memory leak.
> 
> Freeing h5->rx_skb and setting it to NULL, fixes this memory leak.
> 
> Fixes: ce945552fde4 ("Bluetooth: hci_h5: Add support for serdev enumerated devices")
> Reported-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
> Tested-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
> Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>

Patch looks good to me now:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> ---
> Changes in v5:
> 	* Set h5->rx_skb = NULL unconditionally - to improve code
> 	  readability
> 	* Update commit message accordingly
> 
> Changes in v4:
> 	* Free h5->rx_skb even when hu->serdev
> 	(Suggested by Hans de Goede <hdegoede@redhat.com>)
> 	* If hu->serdev, then assign h5->rx_skb = NULL
> 
> Changes in v3:
> 	* Free h5->rx_skb when !hu->serdev, and fix the memory leak
> 	* Do not incorrectly and unnecessarily call serdev_device_close()
> 
> Changes in v2:
> 	* Fixed the Fixes tag
> 
> 
>  drivers/bluetooth/hci_h5.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
> index e41854e0d79a..0ef253136b06 100644
> --- a/drivers/bluetooth/hci_h5.c
> +++ b/drivers/bluetooth/hci_h5.c
> @@ -245,6 +245,9 @@ static int h5_close(struct hci_uart *hu)
>  	skb_queue_purge(&h5->rel);
>  	skb_queue_purge(&h5->unrel);
>  
> +	kfree_skb(h5->rx_skb);
> +	h5->rx_skb = NULL;
> +
>  	if (h5->vnd && h5->vnd->close)
>  		h5->vnd->close(h5);
>  
> 

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Re: [Linux-kernel-mentees] [PATCH v5] bluetooth: hci_h5: fix memory leak in h5_close

[Marcel Holtmann]

Hi Anant,

> When h5_close() is called, h5 is directly freed when !hu->serdev.
> However, h5->rx_skb is not freed, which causes a memory leak.
> 
> Freeing h5->rx_skb and setting it to NULL, fixes this memory leak.
> 
> Fixes: ce945552fde4 ("Bluetooth: hci_h5: Add support for serdev enumerated devices")
> Reported-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
> Tested-by: syzbot+6ce141c55b2f7aafd1c4@syzkaller.appspotmail.com
> Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
> ---
> Changes in v5:
> 	* Set h5->rx_skb = NULL unconditionally - to improve code
> 	  readability
> 	* Update commit message accordingly
> 
> Changes in v4:
> 	* Free h5->rx_skb even when hu->serdev
> 	(Suggested by Hans de Goede <hdegoede@redhat.com>)
> 	* If hu->serdev, then assign h5->rx_skb = NULL
> 
> Changes in v3:
> 	* Free h5->rx_skb when !hu->serdev, and fix the memory leak
> 	* Do not incorrectly and unnecessarily call serdev_device_close()
> 
> Changes in v2:
> 	* Fixed the Fixes tag
> 
> 
> drivers/bluetooth/hci_h5.c | 3 +++
> 1 file changed, 3 insertions(+)

patch has been applied to bluetooth-next tree.

Regards

Marcel

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