2009-09-19 02:20:16

by Kevin Cernekee

Subject: [PATCH] kaweth: Fix memory leak in kaweth_control()

kaweth_control() never frees the buffer that it allocates for the USB
control message. Test case:

while :; do ifconfig eth2 down ; ifconfig eth2 up ; done

This is a tiny buffer so it is a slow leak. If you want to speed up the
process, you can change the allocation size to e.g. 16384 bytes, and it
will consume several megabytes within a few minutes.

Signed-off-by: Kevin Cernekee <[email protected]>
---
drivers/net/usb/kaweth.c | 18 +++++++++++-------
1 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/net/usb/kaweth.c b/drivers/net/usb/kaweth.c
index e2a39b9..e391ef9 100644
--- a/drivers/net/usb/kaweth.c
+++ b/drivers/net/usb/kaweth.c
@@ -263,6 +263,7 @@ static int kaweth_control(struct kaweth_device *kaweth,
int timeout)
{
struct usb_ctrlrequest *dr;
+ int retval;

dbg("kaweth_control()");

@@ -278,18 +279,21 @@ static int kaweth_control(struct kaweth_device *kaweth,
return -ENOMEM;
}

- dr->bRequestType= requesttype;
+ dr->bRequestType = requesttype;
dr->bRequest = request;
dr->wValue = cpu_to_le16(value);
dr->wIndex = cpu_to_le16(index);
dr->wLength = cpu_to_le16(size);

- return kaweth_internal_control_msg(kaweth->dev,
- pipe,
- dr,
- data,
- size,
- timeout);
+ retval = kaweth_internal_control_msg(kaweth->dev,
+ pipe,
+ dr,
+ data,
+ size,
+ timeout);
+
+ kfree(dr);
+ return retval;
}

/****************************************************************
--
1.6.3.1

2009-09-19 19:18:01

by Oliver Neukum

Subject: Re: [PATCH] kaweth: Fix memory leak in kaweth_control()

Am Samstag, 19. September 2009 03:43:30 schrieb Kevin Cernekee:
> kaweth_control() never frees the buffer that it allocates for the USB
> control message. Test case:
>
> while :; do ifconfig eth2 down ; ifconfig eth2 up ; done
>
> This is a tiny buffer so it is a slow leak. If you want to speed up the
> process, you can change the allocation size to e.g. 16384 bytes, and it
> will consume several megabytes within a few minutes.

You are right, the patch is correct. But it has to go to netdev, as it
is for a network driver. Please resend it and add
Acked-by: Oliver Neukum <[email protected]>

Greg, it should go into stable, too.

Regards
Oliver

2009-09-22 21:18:57

by David Miller

Subject: Re: [PATCH] kaweth: Fix memory leak in kaweth_control()

From: Kevin Cernekee <[email protected]>
Date: Fri, 18 Sep 2009 18:43:30 -0700

> kaweth_control() never frees the buffer that it allocates for the USB
> control message. Test case:
>
> while :; do ifconfig eth2 down ; ifconfig eth2 up ; done
>
> This is a tiny buffer so it is a slow leak. If you want to speed up the
> process, you can change the allocation size to e.g. 16384 bytes, and it
> will consume several megabytes within a few minutes.
>
> Signed-off-by: Kevin Cernekee <[email protected]>

Applied, thanks.

I've been trying to wait to give time for people like david-b
to review and bless the various USB networking patches that have
been posted over the past few weeks but I'm running out of
patience :-)

So simple ones like this I'm just gonna apply.