staging: vchiq_core: handle NULL result of find_service_by_handle

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>

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 b32cd12..8f99272 100644 (file)
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -2292,6 +2292,9 @@ 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))
@@ -2312,6 +2315,9 @@ 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;