From: Saurabh Sengar <ssengar@linux.microsoft.com>

For primary VMBus channels primary_channel pointer is always NULL. This
pointer is valid only for the secondry channels.

Fix NULL pointer dereference by retrieving the device_obj from the parent
in the absence of a valid primary_channel pointer.

Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support")
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
---
 drivers/uio/uio_hv_generic.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index b45653752301..c99890c16d29 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -109,7 +109,8 @@ static void hv_uio_channel_cb(void *context)
  */
 static void hv_uio_rescind(struct vmbus_channel *channel)
 {
-	struct hv_device *hv_dev = channel->primary_channel->device_obj;
+	struct hv_device *hv_dev = channel->primary_channel ?
+				   channel->primary_channel->device_obj : channel->device_obj;
 	struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);
 
 	/*
-- 
2.34.1

On Thu, Aug 22, 2024 at 04:39:11PM +0530, Naman Jain wrote:
> From: Saurabh Sengar <ssengar@linux.microsoft.com>
> 
> For primary VMBus channels primary_channel pointer is always NULL. This
> pointer is valid only for the secondry channels.
> 
> Fix NULL pointer dereference by retrieving the device_obj from the parent
> in the absence of a valid primary_channel pointer.
> 
> Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support")
> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
> ---
>  drivers/uio/uio_hv_generic.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 

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