[PATCH][next] drm/selftests/test-drm_dp_mst_helper: fix memory leak allocated to 'out'

[PATCH][next] drm/selftests/test-drm_dp_mst_helper: fix memory leak allocated to 'out'

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

Currently when txmsg fails to allocate then there is a leak on 'out'. Fix
this by setting result to false and exiting via the clean up exit path.
Note since txmsg is NULL at this point, the kfree of txmsg is a no-op.

Addresses-Coverity: ("Resource leak")
Fixes: 09234b88ef55 ("drm/selftests/test-drm_dp_mst_helper: Move 'sideband_msg_req_encode_decode' onto the heap")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
index 6b4759ed6bfd..dbac073ed385 100644
--- a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
+++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
@@ -131,8 +131,10 @@ sideband_msg_req_encode_decode(struct drm_dp_sideband_msg_req_body *in)
 		return false;
 
 	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
-	if (!txmsg)
-		return false;
+	if (!txmsg) {
+		result = false;
+		goto out;
+	}
 
 	drm_dp_encode_sideband_req(in, txmsg);
 	ret = drm_dp_decode_sideband_req(txmsg, out);
-- 
2.28.0

Re: [PATCH][next] drm/selftests/test-drm_dp_mst_helper: fix memory leak allocated to 'out'

[Lee Jones]

On Wed, 18 Nov 2020, Colin King wrote:

> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently when txmsg fails to allocate then there is a leak on 'out'. Fix
> this by setting result to false and exiting via the clean up exit path.
> Note since txmsg is NULL at this point, the kfree of txmsg is a no-op.
> 
> Addresses-Coverity: ("Resource leak")
> Fixes: 09234b88ef55 ("drm/selftests/test-drm_dp_mst_helper: Move 'sideband_msg_req_encode_decode' onto the heap")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

This is fixed in my local branch.

Looks like the wrong version of the patch was sent/applied.

Either way, thanks for the fix Colin.

Reviewed-by: Lee Jones <lee.jones@linaro.org>

> diff --git a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> index 6b4759ed6bfd..dbac073ed385 100644
> --- a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> +++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> @@ -131,8 +131,10 @@ sideband_msg_req_encode_decode(struct drm_dp_sideband_msg_req_body *in)
>  		return false;
>  
>  	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> -	if (!txmsg)
> -		return false;
> +	if (!txmsg) {
> +		result = false;
> +		goto out;
> +	}
>  
>  	drm_dp_encode_sideband_req(in, txmsg);
>  	ret = drm_dp_decode_sideband_req(txmsg, out);

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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