On Thu, Jul 17, 2025 at 10:23:07AM +0800, Ma Ke wrote:
The fsl_mc_get_endpoint() function may call fsl_mc_device_lookup() twice, which would increment the device's reference count twice if both lookups find a device. This could lead to a reference count leak.
Found by code review.
Cc: stable@vger.kernel.org Fixes: 1ac210d128ef ("bus: fsl-mc: add the fsl_mc_get_endpoint function")
I think this should be:
Fixes: 8567494cebe5 ("bus: fsl-mc: rescan devices if endpoint not found")
I've CCed Laurentiu, the author of that commit.
Signed-off-by: Ma Ke make24@iscas.ac.cn
Suggested-by: Simon Horman horms@kernel.org Reviewed-by: Simon Horman horms@kernel.org
drivers/bus/fsl-mc/fsl-mc-bus.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 7671bd158545..c1c0a4759c7e 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -943,6 +943,7 @@ struct fsl_mc_device *fsl_mc_get_endpoint(struct fsl_mc_device *mc_dev, struct fsl_mc_obj_desc endpoint_desc = {{ 0 }}; struct dprc_endpoint endpoint1 = {{ 0 }}; struct dprc_endpoint endpoint2 = {{ 0 }};
- struct fsl_mc_bus *mc_bus; int state, err;
mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent); @@ -966,6 +967,8 @@ struct fsl_mc_device *fsl_mc_get_endpoint(struct fsl_mc_device *mc_dev, strcpy(endpoint_desc.type, endpoint2.type); endpoint_desc.id = endpoint2.id; endpoint = fsl_mc_device_lookup(&endpoint_desc, mc_bus_dev);
- if (endpoint)
return endpoint;/* * We know that the device has an endpoint because we verified by @@ -973,17 +976,13 @@ struct fsl_mc_device *fsl_mc_get_endpoint(struct fsl_mc_device *mc_dev, * yet discovered by the fsl-mc bus, thus the lookup returned NULL. * Force a rescan of the devices in this container and retry the lookup. */
- if (!endpoint) {
struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);if (mutex_trylock(&mc_bus->scan_mutex)) {err = dprc_scan_objects(mc_bus_dev, true);mutex_unlock(&mc_bus->scan_mutex);}if (err < 0)return ERR_PTR(err);
- mc_bus = to_fsl_mc_bus(mc_bus_dev);
- if (mutex_trylock(&mc_bus->scan_mutex)) {
err = dprc_scan_objects(mc_bus_dev, true);mutex_unlock(&mc_bus->scan_mutex);- if (err < 0)
return ERR_PTR(err);endpoint = fsl_mc_device_lookup(&endpoint_desc, mc_bus_dev); /* -- 2.25.1