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* [PATCH v2] soundwire: intel_init: test link->cdns
@ 2021-04-06  1:01 Bard Liao
  2021-04-06  4:56 ` Vinod Koul
  0 siblings, 1 reply; 2+ messages in thread
From: Bard Liao @ 2021-04-06  1:01 UTC (permalink / raw)
  To: alsa-devel, vkoul
  Cc: vinod.koul, linux-kernel, gregkh, srinivas.kandagatla,
	rander.wang, hui.wang, pierre-louis.bossart, sanyog.r.kale,
	bard.liao

intel_link_probe() could return error and dev_get_drvdata() will return
null in such case. So we have to test link->cdns after
link->cdns = dev_get_drvdata(&ldev->auxdev.dev);
Otherwise, we will meet the "kernel NULL pointer dereference" error.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
v2:
 - Rebase to latest code base.
---
 drivers/soundwire/intel_init.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c
index 05b726cdfebc..30ce95ec2d70 100644
--- a/drivers/soundwire/intel_init.c
+++ b/drivers/soundwire/intel_init.c
@@ -178,6 +178,15 @@ static struct sdw_intel_ctx
 		link->pdev = pdev;
 		link->cdns = platform_get_drvdata(pdev);
 
+		if (!link->cdns) {
+			dev_err(&adev->dev, "failed to get link->cdns\n");
+			/*
+			 * 1 will be subtracted from i in the err label, but we need to call
+			 * intel_link_dev_unregister for this ldev, so plus 1 now
+			 */
+			i++;
+			goto err;
+		}
 		list_add_tail(&link->list, &ctx->link_list);
 		bus = &link->cdns->bus;
 		/* Calculate number of slaves */
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH v2] soundwire: intel_init: test link->cdns
  2021-04-06  1:01 [PATCH v2] soundwire: intel_init: test link->cdns Bard Liao
@ 2021-04-06  4:56 ` Vinod Koul
  0 siblings, 0 replies; 2+ messages in thread
From: Vinod Koul @ 2021-04-06  4:56 UTC (permalink / raw)
  To: Bard Liao
  Cc: alsa-devel, linux-kernel, gregkh, srinivas.kandagatla,
	rander.wang, hui.wang, pierre-louis.bossart, sanyog.r.kale,
	bard.liao

On 06-04-21, 09:01, Bard Liao wrote:
> intel_link_probe() could return error and dev_get_drvdata() will return
> null in such case. So we have to test link->cdns after
> link->cdns = dev_get_drvdata(&ldev->auxdev.dev);
> Otherwise, we will meet the "kernel NULL pointer dereference" error.

Applied, thanks

-- 
~Vinod

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2021-04-06  4:57 UTC | newest]

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2021-04-06  1:01 [PATCH v2] soundwire: intel_init: test link->cdns Bard Liao
2021-04-06  4:56 ` Vinod Koul

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