mfd: altera-sysmgr: fix device leak on sysmgr regmap lookup

[PATCH] mfd: altera-sysmgr: fix device leak on sysmgr regmap lookup

Posted by Johan Hovold 6 days, 8 hours ago

Make sure to drop the reference taken to the sysmgr platform device when
retrieving its driver data.

Note that holding a reference to a device does not prevent its driver
data from going away.

Fixes: f36e789a1f8d ("mfd: altera-sysmgr: Add SOCFPGA System Manager")
Cc: stable@vger.kernel.org	# 5.2
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/mfd/altera-sysmgr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mfd/altera-sysmgr.c b/drivers/mfd/altera-sysmgr.c
index fb5f988e61f3..90c6902d537d 100644
--- a/drivers/mfd/altera-sysmgr.c
+++ b/drivers/mfd/altera-sysmgr.c
@@ -117,6 +117,8 @@ struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np,
 
 	sysmgr = dev_get_drvdata(dev);
 
+	put_device(dev);
+
 	return sysmgr->regmap;
 }
 EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);
-- 
2.49.1

Re: [PATCH] mfd: altera-sysmgr: fix device leak on sysmgr regmap lookup

Posted by Markus Elfring 5 days, 3 hours ago

> Make sure to drop the reference taken to the sysmgr platform device when
> retrieving its driver data.
…

How do you think about to increase the application of scope-based resource management?
https://elixir.bootlin.com/linux/v6.17-rc7/source/include/linux/device.h#L1180

Regards,
Markus