* [PATCH] comedi: usbdux: free allocated memory/urbs on failure
@ 2021-07-15 2:26 Salah Triki
2021-07-15 11:34 ` Ian Abbott
0 siblings, 1 reply; 2+ messages in thread
From: Salah Triki @ 2021-07-15 2:26 UTC (permalink / raw)
To: abbotti, hsweeten, gregkh; +Cc: linux-kernel
Free allocated memory/urbs on failure in order to prevent memory leaks.
Signed-off-by: Salah Triki <salah.triki@gmail.com>
---
drivers/comedi/drivers/usbdux.c | 42 ++++++++++++++++++++++++++++-----
1 file changed, 36 insertions(+), 6 deletions(-)
diff --git a/drivers/comedi/drivers/usbdux.c b/drivers/comedi/drivers/usbdux.c
index 0350f303d557..fe388a9a588a 100644
--- a/drivers/comedi/drivers/usbdux.c
+++ b/drivers/comedi/drivers/usbdux.c
@@ -1456,7 +1456,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
/* one frame: 1ms */
urb = usb_alloc_urb(1, GFP_KERNEL);
if (!urb)
- return -ENOMEM;
+ goto free_ai_urbs1;
devpriv->ai_urbs[i] = urb;
urb->dev = usb;
@@ -1465,7 +1465,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
urb->transfer_flags = URB_ISO_ASAP;
urb->transfer_buffer = kzalloc(SIZEINBUF, GFP_KERNEL);
if (!urb->transfer_buffer)
- return -ENOMEM;
+ goto free_ai_urbs2;
urb->complete = usbduxsub_ai_isoc_irq;
urb->number_of_packets = 1;
@@ -1478,7 +1478,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
/* one frame: 1ms */
urb = usb_alloc_urb(1, GFP_KERNEL);
if (!urb)
- return -ENOMEM;
+ goto free_ao_urbs1;
devpriv->ao_urbs[i] = urb;
urb->dev = usb;
@@ -1487,7 +1487,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
urb->transfer_flags = URB_ISO_ASAP;
urb->transfer_buffer = kzalloc(SIZEOUTBUF, GFP_KERNEL);
if (!urb->transfer_buffer)
- return -ENOMEM;
+ goto free_ao_urbs2;
urb->complete = usbduxsub_ao_isoc_irq;
urb->number_of_packets = 1;
@@ -1504,17 +1504,47 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
if (devpriv->pwm_buf_sz) {
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb)
- return -ENOMEM;
+ goto free_ao_urbs0;
devpriv->pwm_urb = urb;
/* max bulk ep size in high speed */
urb->transfer_buffer = kzalloc(devpriv->pwm_buf_sz,
GFP_KERNEL);
if (!urb->transfer_buffer)
- return -ENOMEM;
+ goto free_urb;
}
return 0;
+
+free_urb:
+ usb_free_urb(urb);
+
+free_ao_urbs0:
+ i = devpriv->n_ao_urbs;
+
+free_ao_urbs1:
+ i--;
+
+free_ao_urbs2:
+ while (i >= 0) {
+ kfree(devpriv->ao_urbs[i]->transfer_buffer);
+ usb_free_urb(devpriv->ao_urbs[i]);
+ i--;
+ }
+ i = devpriv->n_ai_urbs;
+
+free_ai_urbs1:
+ i--;
+
+free_ai_urbs2:
+ while (i >= 0) {
+ kfree(devpriv->ai_urbs[i]->transfer_buffer);
+ usb_free_urb(devpriv->ai_urbs[i]);
+ i--;
+ }
+
+ return -ENOMEM;
+
}
static void usbdux_free_usb_buffers(struct comedi_device *dev)
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] comedi: usbdux: free allocated memory/urbs on failure
2021-07-15 2:26 [PATCH] comedi: usbdux: free allocated memory/urbs on failure Salah Triki
@ 2021-07-15 11:34 ` Ian Abbott
0 siblings, 0 replies; 2+ messages in thread
From: Ian Abbott @ 2021-07-15 11:34 UTC (permalink / raw)
To: Salah Triki, hsweeten, gregkh; +Cc: linux-kernel
On 15/07/2021 03:26, Salah Triki wrote:
> Free allocated memory/urbs on failure in order to prevent memory leaks.
>
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> ---
> drivers/comedi/drivers/usbdux.c | 42 ++++++++++++++++++++++++++++-----
> 1 file changed, 36 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/comedi/drivers/usbdux.c b/drivers/comedi/drivers/usbdux.c
> index 0350f303d557..fe388a9a588a 100644
> --- a/drivers/comedi/drivers/usbdux.c
> +++ b/drivers/comedi/drivers/usbdux.c
> @@ -1456,7 +1456,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
> /* one frame: 1ms */
> urb = usb_alloc_urb(1, GFP_KERNEL);
> if (!urb)
> - return -ENOMEM;
> + goto free_ai_urbs1;
> devpriv->ai_urbs[i] = urb;
>
> urb->dev = usb;
> @@ -1465,7 +1465,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
> urb->transfer_flags = URB_ISO_ASAP;
> urb->transfer_buffer = kzalloc(SIZEINBUF, GFP_KERNEL);
> if (!urb->transfer_buffer)
> - return -ENOMEM;
> + goto free_ai_urbs2;
>
> urb->complete = usbduxsub_ai_isoc_irq;
> urb->number_of_packets = 1;
> @@ -1478,7 +1478,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
> /* one frame: 1ms */
> urb = usb_alloc_urb(1, GFP_KERNEL);
> if (!urb)
> - return -ENOMEM;
> + goto free_ao_urbs1;
> devpriv->ao_urbs[i] = urb;
>
> urb->dev = usb;
> @@ -1487,7 +1487,7 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
> urb->transfer_flags = URB_ISO_ASAP;
> urb->transfer_buffer = kzalloc(SIZEOUTBUF, GFP_KERNEL);
> if (!urb->transfer_buffer)
> - return -ENOMEM;
> + goto free_ao_urbs2;
>
> urb->complete = usbduxsub_ao_isoc_irq;
> urb->number_of_packets = 1;
> @@ -1504,17 +1504,47 @@ static int usbdux_alloc_usb_buffers(struct comedi_device *dev)
> if (devpriv->pwm_buf_sz) {
> urb = usb_alloc_urb(0, GFP_KERNEL);
> if (!urb)
> - return -ENOMEM;
> + goto free_ao_urbs0;
> devpriv->pwm_urb = urb;
>
> /* max bulk ep size in high speed */
> urb->transfer_buffer = kzalloc(devpriv->pwm_buf_sz,
> GFP_KERNEL);
> if (!urb->transfer_buffer)
> - return -ENOMEM;
> + goto free_urb;
> }
>
> return 0;
> +
> +free_urb:
> + usb_free_urb(urb);
> +
> +free_ao_urbs0:
> + i = devpriv->n_ao_urbs;
> +
> +free_ao_urbs1:
> + i--;
> +
> +free_ao_urbs2:
> + while (i >= 0) {
> + kfree(devpriv->ao_urbs[i]->transfer_buffer);
> + usb_free_urb(devpriv->ao_urbs[i]);
> + i--;
> + }
> + i = devpriv->n_ai_urbs;
> +
> +free_ai_urbs1:
> + i--;
> +
> +free_ai_urbs2:
> + while (i >= 0) {
> + kfree(devpriv->ai_urbs[i]->transfer_buffer);
> + usb_free_urb(devpriv->ai_urbs[i]);
> + i--;
> + }
> +
> + return -ENOMEM;
> +
> }
>
> static void usbdux_free_usb_buffers(struct comedi_device *dev)
>
NAK.
Actually, there is no need for this because usbdux_free_usb_buffers()
will soon be called to clean up when this fails.[*] Also, it isn't
cleaning up enough to prevent double frees when
usbdux_free_usb_buffers() is called later.
[*] The error returned from usbdux_alloc_usb_buffers() is propagated as
an error returned by usbdux_auto_attach(). The Comedi core calls the
"detach()" handler (usbdux_detach()) to clean up when the
"auto_attach()" handler (usbdux_auto_attach()) returns an error.
usbdux_detach() calls usbdux_free_usb_buffers() to clean up the
(possibly partial) allocations done by usbdux_alloc_usb_buffers().
--
-=( Ian Abbott <abbotti@mev.co.uk> || MEV Ltd. is a company )=-
-=( registered in England & Wales. Regd. number: 02862268. )=-
-=( Regd. addr.: S11 & 12 Building 67, Europa Business Park, )=-
-=( Bird Hall Lane, STOCKPORT, SK3 0XA, UK. || www.mev.co.uk )=-
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-07-15 11:34 ` Ian Abbott
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