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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Nicolas Saenz Julienne <nsaenz@kernel.org>,
        Stefan Wahren <stefan.wahren@i2se.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 117/285] staging: vchiq_core: handle NULL result of find_service_by_handle
Date:   Tue, 12 Apr 2022 08:29:34 +0200
Message-Id: <20220412062947.043429848@linuxfoundation.org>
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From: Stefan Wahren <stefan.wahren@i2se.com>

[ Upstream commit ca225857faf237234d2fffe5d1919467dfadd822 ]

In case of an invalid handle the function find_servive_by_handle
returns NULL. So take care of this and avoid a NULL pointer dereference.

Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1642968143-19281-18-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../staging/vc04_services/interface/vchiq_arm/vchiq_core.c  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
index 7fe20d4b7ba2..b7295236671c 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -2306,6 +2306,9 @@ void vchiq_msg_queue_push(unsigned int handle, struct vchiq_header *header)
 	struct vchiq_service *service = find_service_by_handle(handle);
 	int pos;
 
+	if (!service)
+		return;
+
 	while (service->msg_queue_write == service->msg_queue_read +
 		VCHIQ_MAX_SLOTS) {
 		if (wait_for_completion_interruptible(&service->msg_queue_pop))
@@ -2326,6 +2329,9 @@ struct vchiq_header *vchiq_msg_hold(unsigned int handle)
 	struct vchiq_header *header;
 	int pos;
 
+	if (!service)
+		return NULL;
+
 	if (service->msg_queue_write == service->msg_queue_read)
 		return NULL;
 
-- 
2.35.1