From: Dan Williams Date: Fri, 11 Feb 2022 01:04:42 +0000 (-0800) Subject: cxl/port: Fix endpoint refcount leak X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=41ae9105f5e23e98a1734be2eeddddf488e42c2e;p=linux.git cxl/port: Fix endpoint refcount leak An endpoint can be unregistered via two paths. Either its parent port is unregistered, or the memdev that registered the endpoint is removed. The memdev remove path is responsible for synchronizing against the parent ->remove() event and if the memdev remove path wins, manually trigger unregister_port() via devm_release_action(). Until that race is resolved the memdev remove path holds a reference on the endpoint. If the parent port for the endpoint can not be found that is an indication that the endpoint has already been registered. Be sure to drop the reference in all exit paths from delete_endpoint(). Fixes: 8dd2bc0f8e02 ("cxl/mem: Add the cxl_mem driver") Link: https://lore.kernel.org/r/164454148209.3429624.12905500880311609053.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams --- diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index d29eb2abdbc23..0fc1441be0141 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -850,7 +850,7 @@ static void delete_endpoint(void *data) parent_port = cxl_mem_find_port(cxlmd); if (!parent_port) - return; + goto out; parent = &parent_port->dev; cxl_device_lock(parent); @@ -860,6 +860,7 @@ static void delete_endpoint(void *data) } cxl_device_unlock(parent); put_device(parent); +out: put_device(&endpoint->dev); }