[PATCH] staging: bcm2835-audio: Fix memory corruption
dan.carpenter at oracle.com
Thu Aug 10 03:21:55 PDT 2017
The original patch did not go through the normal review process...
On Tue, Aug 08, 2017 at 01:05:02PM +0100, Phil Elwell wrote:
> I'm all for fixing memory leaks, but freeing a block while it is still
> being used is a recipe for hard-to-debug kernel exceptions.
This bug completely breaks the driver doesn't it? It's not very subtle
so it should be easy to diagnose with git bisect.
> 1) There is already a vchi method for freeing the instance, so use it.
> 2) Only call it on error, and then only before initted is false.
> Signed-off-by: Phil Elwell <phil at raspberrypi.org>
> Fixes: 0adbfd4694c2 ("staging: bcm2835-audio: fix memory leak in bcm2835_audio_open_connection()")
> drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> index 5f3d8f2..89f96f3 100644
> --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> @@ -409,6 +409,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
> LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n",
> __func__, ret);
> + vchi_disconnect(vchi_instance);
This is ugly because why are we calling disconnect() if connect() fails?
These functions should be symetric so disconnect only disconnects and
we call a different function to undo vchi_initialise().
> ret = -EIO;
> goto err_free_mem;
This label name is out of date. There is a later error path where
vc_vchi_audio_init() fails and we leak on that path. Also why is
vchi_instance a static variable? Arglebargleblargleblah...
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