From fdfcf82204737e45bfaa27a4fc65298990dfac07 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 23 Aug 2019 08:12:59 -0300 Subject: [PATCH] media: cec-notifier: clear cec_adap in cec_notifier_unregister [ Upstream commit 14d5511691e5290103bc480998bc322e68f139d4 ] If cec_notifier_cec_adap_unregister() is called before cec_unregister_adapter() then everything is OK (and this is the case today). But if it is the other way around, then cec_notifier_unregister() is called first, and that doesn't set n->cec_adap to NULL. So if e.g. cec_notifier_set_phys_addr() is called after cec_notifier_unregister() but before cec_unregister_adapter() then n->cec_adap points to an unregistered and likely deleted cec adapter. So just set n->cec_adap->notifier and n->cec_adap to NULL for rubustness. Eventually cec_notifier_unregister will disappear and this will be simplified substantially. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/cec/cec-notifier.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/media/cec/cec-notifier.c b/drivers/media/cec/cec-notifier.c index 08b619d0ea1e..cd04499df489 100644 --- a/drivers/media/cec/cec-notifier.c +++ b/drivers/media/cec/cec-notifier.c @@ -130,6 +130,8 @@ void cec_notifier_unregister(struct cec_notifier *n) { mutex_lock(&n->lock); n->callback = NULL; + n->cec_adap->notifier = NULL; + n->cec_adap = NULL; mutex_unlock(&n->lock); cec_notifier_put(n); } -- 2.20.1