[PATCH 4.11 110/197] [media] cec: Fix runtime BUG when (CONFIG_RC_CORE && !CEC_CAP_RC)

[Greg Kroah-Hartman]

4.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lee Jones <lee.jones@xxxxxxxxxx>

commit 43c0c03961d0b19bd225a336897606b46e0021a6 upstream.

Currently when the RC Core is enabled (reachable) core code located
in cec_register_adapter() attempts to populate the RC structure with
a pointer to the 'parent' passed in by the caller.

Unfortunately if the caller did not specify RC capability when calling
cec_allocate_adapter(), then there will be no RC structure to populate.

This causes a "NULL pointer dereference" error.

Fixes: f51e80804f0 ("[media] cec: pass parent device in register(), not allocate()")

Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/media/cec/cec-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/media/cec/cec-core.c
+++ b/drivers/media/cec/cec-core.c
@@ -286,8 +286,8 @@ int cec_register_adapter(struct cec_adap
 	adap->devnode.dev.parent = parent;
 
 #if IS_REACHABLE(CONFIG_RC_CORE)
-	adap->rc->dev.parent = parent;
 	if (adap->capabilities & CEC_CAP_RC) {
+		adap->rc->dev.parent = parent;
 		res = rc_register_device(adap->rc);
 
 		if (res) {