altr_sysmgr_regmap_lookup_by_phandle() utilizes driver_find_device_by_of_node() which internally calls driver_find_device() to locate the matching device. driver_find_device() increments the ref count of the found device by calling get_device(), but altr_sysmgr_regmap_lookup_by_phandle() fails to call put_device() to decrement the reference count before returning. This results in a reference count leak of the device, which may prevent the device from being properly released and cause a memory leak.

Found by code review.

Cc: stable@vger.kernel.org Fixes: cfba5de9b99f ("drivers: Introduce device lookup variants by of_node") Signed-off-by: Ma Ke make24@iscas.ac.cn --- drivers/mfd/altera-sysmgr.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/altera-sysmgr.c b/drivers/mfd/altera-sysmgr.c index fb5f988e61f3..c6c763fb7bbe 100644 --- a/drivers/mfd/altera-sysmgr.c +++ b/drivers/mfd/altera-sysmgr.c @@ -98,6 +98,7 @@ struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np, struct device *dev; struct altr_sysmgr *sysmgr; struct device_node *sysmgr_np; + struct regmap *regmap;

if (property) sysmgr_np = of_parse_phandle(np, property, 0); @@ -116,8 +117,10 @@ struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np, return ERR_PTR(-EPROBE_DEFER);

sysmgr = dev_get_drvdata(dev); + regmap = sysmgr->regmap; + put_device(dev);

- return sysmgr->regmap; + return regmap; } EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);