linux-stable/drivers/media
Jesper Juhl 7e270941c8 [media] Zarlink zl10036 DVB-S: Fix mem leak in zl10036_attach
On Thu, 17 Feb 2011, Matthias Schwarzott wrote:

> On Sunday 06 February 2011, Jesper Juhl wrote:
> > If the memory allocation to 'state' succeeds but we jump to the 'error'
> > label before 'state' is assigned to fe->tuner_priv, then the call to
> > 'zl10036_release(fe)' at the 'error:' label will not free 'state', but
> > only what was previously assigned to 'tuner_priv', thus leaking the memory
> > allocated to 'state'.
> > There are may ways to fix this, including assigning the allocated memory
> > directly to 'fe->tuner_priv', but I did not go for that since the
> > additional pointer derefs are more expensive than the local variable, so I
> > just added a 'kfree(state)' call. I guess the call to 'zl10036_release'
> > might not even be needed in this case, but I wasn't sure, so I left it in.
> >
> Yeah, that call to zl10036_release can be completely eleminated.
> Another thing is: jumping to the error label only makes sense when memory was
> already allocated. So the jump in line 471 can be replaced by "return NULL",
> as the other error handling before allocation:
>         if (NULL == config) {
>                 printk(KERN_ERR "%s: no config specified", __func__);
>                 goto error;
>         }
>
> I suggest to improve the patch to clean the code up when changing that.
>
> But I am fine with commiting this patch also if you do not want to change it.
>

Thank you for your feedback. It makes a lot of sense.
Changing it is not a problem :)
How about the updated patch below?

If the memory allocation to 'state' succeeds but we jump to the 'error'
label before 'state' is assigned to fe->tuner_priv, then the call to
'zl10036_release(fe)' at the 'error:' label will not free 'state', but
only what was previously assigned to 'tuner_priv', thus leaking the memory
allocated to 'state'.
This patch fixes the leak and also does not jump to 'error:' before mem
has been allocated but instead just returns. Also some small style
cleanups.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-03-22 06:51:55 -03:00
..
common [media] tuner-xc2028.c: fix compile warning 2011-03-22 04:53:58 -03:00
dvb [media] Zarlink zl10036 DVB-S: Fix mem leak in zl10036_attach 2011-03-22 06:51:55 -03:00
radio [media] fmdrv_common.c: fix compiler warning 2011-03-22 04:54:02 -03:00
rc [media] add TerraTec remote 2011-03-22 04:54:55 -03:00
video [media] V4L: videobuf, don't use dma addr as physical 2011-03-22 06:51:54 -03:00
Kconfig [media] v4l: Create v4l2 subdev file handle structure 2011-03-22 04:53:26 -03:00
Makefile [media] media: Entities, pads and links 2011-03-22 04:53:10 -03:00
media-device.c [media] media: Links setup 2011-03-22 04:53:16 -03:00
media-devnode.c [media] media: Media device node support 2011-03-22 04:52:22 -03:00
media-entity.c [media] media: Pipelines and media streams 2011-03-22 04:53:17 -03:00