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SubjectRe: [PATCH v2] staging: bcm2835-audio: Fix memory corruption
Hi Greg,

> Phil Elwell <phil@raspberrypi.org> hat am 11. August 2017 um 12:20 geschrieben:
>
>
> The previous commit (0adbfd46) fixed a memory leak but also freed a
> block in the success case, causing a stale pointer to be used with
> potentially fatal results. Only free the vchi_instance block in the
> case that vchi_connect fails; once connected, the instance is
> retained for subsequent connections.
>
> Simplifying the code by removing a bunch of gotos and returning errors
> directly.
>
> Signed-off-by: Phil Elwell <phil@raspberrypi.org>
> Fixes: 0adbfd4694c2 ("staging: bcm2835-audio: fix memory leak in bcm2835_audio_open_connection()")

can you still apply this patch or do you need a resend?

> ---
> [Resend with v2 in subject]
> v2: Simplified following feedback from Dan Carpenter.
> ---
> .../vc04_services/bcm2835-audio/bcm2835-vchiq.c | 19 +++++++------------
> 1 file changed, 7 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> index 5f3d8f2..4be864d 100644
> --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
> @@ -390,8 +390,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
> __func__, instance);
> instance->alsa_stream = alsa_stream;
> alsa_stream->instance = instance;
> - ret = 0; // xxx todo -1;
> - goto err_free_mem;
> + return 0;
> }
>
> /* Initialize and create a VCHI connection */
> @@ -401,16 +400,15 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
> LOG_ERR("%s: failed to initialise VCHI instance (ret=%d)\n",
> __func__, ret);
>
> - ret = -EIO;
> - goto err_free_mem;
> + return -EIO;
> }
> ret = vchi_connect(NULL, 0, vchi_instance);
> if (ret) {
> LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n",
> __func__, ret);
>
> - ret = -EIO;
> - goto err_free_mem;
> + kfree(vchi_instance);
> + return -EIO;
> }
> initted = 1;
> }
> @@ -421,19 +419,16 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream
> if (IS_ERR(instance)) {
> LOG_ERR("%s: failed to initialize audio service\n", __func__);
>
> - ret = PTR_ERR(instance);
> - goto err_free_mem;
> + /* vchi_instance is retained for use the next time. */
> + return PTR_ERR(instance);
> }
>
> instance->alsa_stream = alsa_stream;
> alsa_stream->instance = instance;
>
> LOG_DBG(" success !\n");
> - ret = 0;
> -err_free_mem:
> - kfree(vchi_instance);
>
> - return ret;
> + return 0;
> }
>
> int bcm2835_audio_open(struct bcm2835_alsa_stream *alsa_stream)
> --
> 1.9.1
>

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