[PATCH v1 2/5] devres: Fix memory leakage caused by driver API devm_free_percpu()

From: Zijun Hu
Date: Tue Jul 02 2024 - 10:53:42 EST


It will cause memory leakage when use driver API devm_free_percpu()
to free memory allocated by devm_alloc_percpu(), fixed by using
devres_release() instead of devres_destroy() within devm_free_percpu().

Fixes: ff86aae3b411 ("devres: add devm_alloc_percpu()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
Previous discussion link:
https://lore.kernel.org/lkml/1718804281-1796-1-git-send-email-quic_zijuhu@xxxxxxxxxxx/

drivers/base/devres.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index ff2247eec43c..8d709dbd4e0c 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -1225,7 +1225,11 @@ EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
*/
void devm_free_percpu(struct device *dev, void __percpu *pdata)
{
- WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
+ /*
+ * Use devres_release() to prevent memory leakage as
+ * devm_free_pages() does.
+ */
+ WARN_ON(devres_release(dev, devm_percpu_release, devm_percpu_match,
(__force void *)pdata));
}
EXPORT_SYMBOL_GPL(devm_free_percpu);
--
2.34.1