6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ma Ke make24@iscas.ac.cn
commit bddbe13d36a02d5097b99cf02354d5752ad1ac60 upstream.
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") Signed-off-by: Ma Ke make24@iscas.ac.cn Tested-by: Ioana Ciornei ioana.ciornei@nxp.com Reviewed-by: Simon Horman horms@kernel.org Fixes: 8567494cebe5 ("bus: fsl-mc: rescan devices if endpoint not found") Link: https://patch.msgid.link/20250717022309.3339976-1-make24@iscas.ac.cn Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/bus/fsl-mc/fsl-mc-bus.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -942,6 +942,7 @@ struct fsl_mc_device *fsl_mc_get_endpoin 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); @@ -965,6 +966,8 @@ struct fsl_mc_device *fsl_mc_get_endpoin 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 @@ -972,17 +975,13 @@ struct fsl_mc_device *fsl_mc_get_endpoin * 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); /*