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.l...@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridha...@linux.intel.com>
Reviewed-by: Rander Wang <rander.w...@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.boss...@linux.intel.com>
---
 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 5b32a2ffd376..5ef5bd0defab 100644
--- a/drivers/soundwire/intel_init.c
+++ b/drivers/soundwire/intel_init.c
@@ -250,6 +250,15 @@ static struct sdw_intel_ctx
                link = &ldev->link_res;
                link->cdns = dev_get_drvdata(&ldev->auxdev.dev);
 
+               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

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