[PATCH] perf: arm_cspmu: fix device leak in arm_cspmu_impl_unregister

[Ma Ke]

arm_cspmu_impl_unregister() utilizes driver_find_device() to locate
matching devices. driver_find_device() increments the ref count of the
found device by calling get_device(), but arm_cspmu_impl_unregister()
fails to call put_device() to decrement the reference count after
processing each device. This results in a reference count leak of the
device objects, which prevents devices from being properly released
and causes a memory leak. Fix the leak by adding put_device() after
device_release_driver() in the while loop.

Found by code review.

Cc: stable at vger.kernel.org
Fixes: bfc653aa89cb ("perf: arm_cspmu: Separate Arm and vendor module")
Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
---
 drivers/perf/arm_cspmu/arm_cspmu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
index efa9b229e701..e0d4293f06f9 100644
--- a/drivers/perf/arm_cspmu/arm_cspmu.c
+++ b/drivers/perf/arm_cspmu/arm_cspmu.c
@@ -1365,8 +1365,10 @@ void arm_cspmu_impl_unregister(const struct arm_cspmu_impl_match *impl_match)
 
 	/* Unbind the driver from all matching backend devices. */
 	while ((dev = driver_find_device(&arm_cspmu_driver.driver, NULL,
-			match, arm_cspmu_match_device)))
+			match, arm_cspmu_match_device))) {
 		device_release_driver(dev);
+		put_device(dev);
+	}
 
 	mutex_lock(&arm_cspmu_lock);
 
-- 
2.17.1