From: Dave Jiang <dave.jiang@intel.com>
Date: Fri, 5 Jan 2024 22:07:46 +0000 (-0700)
Subject: cxl: Fix device reference leak in cxl_port_perf_data_calculate()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=98e7ab3345e105339b7d919b4918f3c1879052ed;p=linux.git

cxl: Fix device reference leak in cxl_port_perf_data_calculate()

cxl_port_perf_data_calculate() calls find_cxl_root() and does not
dereference the 'struct device' in the cxl_root->port. find_cxl_root()
calls get_device() and takes a reference on the port 'struct device'
member. Use the __free() macro to ensure the dereference happens.

Fixes: 7a4f148dd8d5 ("cxl: Compute the entire CXL path latency and bandwidth data")
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/170449246681.3779673.2288926019977963333.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
index 0df5379cf02f5..c6208aab452ff 100644
--- a/drivers/cxl/core/cdat.c
+++ b/drivers/cxl/core/cdat.c
@@ -162,7 +162,6 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port,
 					struct xarray *dsmas_xa)
 {
 	struct access_coordinate c;
-	struct cxl_root *cxl_root;
 	struct dsmas_entry *dent;
 	int valid_entries = 0;
 	unsigned long index;
@@ -174,7 +173,11 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port,
 		return rc;
 	}
 
-	cxl_root = find_cxl_root(port);
+	struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
+
+	if (!cxl_root)
+		return -ENODEV;
+
 	if (!cxl_root->ops || !cxl_root->ops->qos_class)
 		return -EOPNOTSUPP;