2021-07-15 00:59:55

by Salah Triki

Subject: [PATCH] sound: usb: line6: free allocated urbs on failure

Free allocated urbs on failure in order to prevent memory leaks.

Signed-off-by: Salah Triki <[email protected]>
---
sound/usb/line6/capture.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/sound/usb/line6/capture.c b/sound/usb/line6/capture.c
index 970c9bdce0b2..345b75ede5d5 100644
--- a/sound/usb/line6/capture.c
+++ b/sound/usb/line6/capture.c
@@ -258,6 +258,7 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
{
struct usb_line6 *line6 = line6pcm->line6;
int i;
+ int ret;

line6pcm->in.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
GFP_KERNEL);
@@ -272,8 +273,10 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
urb = line6pcm->in.urbs[i] =
usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);

- if (urb == NULL)
- return -ENOMEM;
+ if (urb == NULL) {
+ ret = -ENOMEM;
+ goto enomem;
+ }

urb->dev = line6->usbdev;
urb->pipe =
@@ -286,9 +289,20 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
urb->interval = LINE6_ISO_INTERVAL;
urb->error_count = 0;
urb->complete = audio_in_callback;
- if (usb_urb_ep_type_check(urb))
- return -EINVAL;
+ if (usb_urb_ep_type_check(urb)) {
+ ret = -EINVAL;
+ goto einval;
+ }
}

return 0;
+
+enomem:
+ i--;
+
+einval:
+ while (i >= 0)
+ usb_free_urb(line6pcm->in.urbs[i--]);
+
+ return ret;
}
--
2.25.1

2021-07-15 08:06:35

by Takashi Iwai

Subject: Re: [PATCH] sound: usb: line6: free allocated urbs on failure

On Thu, 15 Jul 2021 02:56:25 +0200,
Salah Triki wrote:
>
> Free allocated urbs on failure in order to prevent memory leaks.
>
> Signed-off-by: Salah Triki <[email protected]>

This will lead to double-free. The resources are freed in the
destructor of PCM component, line6_cleanup_pcm().


Takashi


> ---
> sound/usb/line6/capture.c | 22 ++++++++++++++++++----
> 1 file changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/sound/usb/line6/capture.c b/sound/usb/line6/capture.c
> index 970c9bdce0b2..345b75ede5d5 100644
> --- a/sound/usb/line6/capture.c
> +++ b/sound/usb/line6/capture.c
> @@ -258,6 +258,7 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
> {
> struct usb_line6 *line6 = line6pcm->line6;
> int i;
> + int ret;
>
> line6pcm->in.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
> GFP_KERNEL);
> @@ -272,8 +273,10 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
> urb = line6pcm->in.urbs[i] =
> usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
>
> - if (urb == NULL)
> - return -ENOMEM;
> + if (urb == NULL) {
> + ret = -ENOMEM;
> + goto enomem;
> + }
>
> urb->dev = line6->usbdev;
> urb->pipe =
> @@ -286,9 +289,20 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
> urb->interval = LINE6_ISO_INTERVAL;
> urb->error_count = 0;
> urb->complete = audio_in_callback;
> - if (usb_urb_ep_type_check(urb))
> - return -EINVAL;
> + if (usb_urb_ep_type_check(urb)) {
> + ret = -EINVAL;
> + goto einval;
> + }
> }
>
> return 0;
> +
> +enomem:
> + i--;
> +
> +einval:
> + while (i >= 0)
> + usb_free_urb(line6pcm->in.urbs[i--]);
> +
> + return ret;
> }
> --
> 2.25.1
>