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soc: samsung: exynos-pmu: fix device leak on regmap lookup

PATCH Applied Johan Hovold 2 participants 5 messages Nov 21, 2025 – Nov 27, 2025

Subsystems (2)
Stable branch Arm Samsung Exynos
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Johan Hovold

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#0 lore raw

PATCH 1/1 soc: samsung: exynos-pmu: fix device leak on regmap lookup

Make sure to drop the reference taken when looking up the PMU device and its regmap.

Note that holding a reference to a device does not prevent its regmap from going away so there is no point in keeping the reference.

Fixes 0b7c6075022c ("soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs")
Cc [email protected] # 6.9
Cc Peter Griffin <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/soc/samsung/exynos-pmu.c | 2 ++
 1 file changed, 2 insertions(+)
drivers/soc/samsung/exynos-pmu.c +2 -0
index 22c50ca2aa79..ba4de8194a0e 100644
@@ -346,6 +346,8 @@ struct regmap *exynos_get_pmu_regmap_by_phandle(struct device_node *np,
 	if (!dev)
 		return ERR_PTR(-EPROBE_DEFER);
 
+	put_device(dev);
+
 	return syscon_node_to_regmap(pmu_np);
 }
 EXPORT_SYMBOL_GPL(exynos_get_pmu_regmap_by_phandle);
Signature · 1 line
2.51.2
maintainer
#1 lore raw
Quoted 5 lines · Johan Hovold

Make sure to drop the reference taken when looking up the PMU device and its regmap.

Note that holding a reference to a device does not prevent its regmap from going away so there is no point in keeping the reference.

Thanks for the patch, it's 3rd or fourth try from LKML on that, but you were the only one actually really reading the code instead of sprinking puts all around.

Quoted 3 lines
Fixes 0b7c6075022c ("soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs")
Cc [email protected] # 6.9

Fix is fine, but unfortunately the code in v6.9 was different and I believe keeping dev reference made sense there - driver was relying on drvdata. While the leak was there as well, it was intentional. I think the leak can be fixed only since commit 35d6b98c625867209bc47df99cf03edf4280799f .

Best regards,
Krzysztof

author
#2 lore raw
Quoted 7 lines · Krzysztof Kozlowski
Quoted 5 lines · Johan Hovold

Make sure to drop the reference taken when looking up the PMU device and its regmap.

Note that holding a reference to a device does not prevent its regmap from going away so there is no point in keeping the reference.

Quoted 8 lines
Quoted 2 lines
Fixes 0b7c6075022c ("soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs")
Cc [email protected] # 6.9

Fix is fine, but unfortunately the code in v6.9 was different and I believe keeping dev reference made sense there - driver was relying on drvdata. While the leak was there as well, it was intentional. I think the leak can be fixed only since commit 35d6b98c625867209bc47df99cf03edf4280799f .

It makes no difference actually as holding a reference to a device does not prevent its driver data from going away either.

Johan

maintainer
#3 lore raw
Quoted 11 lines · Johan Hovold
Quoted 10 lines · Krzysztof Kozlowski
Quoted 8 lines · Johan Hovold

Make sure to drop the reference taken when looking up the PMU device and its regmap.

Note that holding a reference to a device does not prevent its regmap from going away so there is no point in keeping the reference.

Fixes 0b7c6075022c ("soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs")
Cc [email protected] # 6.9
Quoted 8 lines
Quoted 5 lines

Fix is fine, but unfortunately the code in v6.9 was different and I believe keeping dev reference made sense there - driver was relying on drvdata. While the leak was there as well, it was intentional. I think the leak can be fixed only since commit 35d6b98c625867209bc47df99cf03edf4280799f .

It makes no difference actually as holding a reference to a device does not prevent its driver data from going away either.

True, fair enough.

Best regards,
Krzysztof

maintainer Applied
#4 lore raw
In reply to Johan Hovold
Quoted 8 lines · Johan Hovold

Make sure to drop the reference taken when looking up the PMU device and its regmap.

Note that holding a reference to a device does not prevent its regmap from going away so there is no point in keeping the reference.

[...]

Applied for late. I might send it during merge window or might miss it and roll for the next one. In any case I will keep it in my tree.

Applied, thanks!

[1/1] soc: samsung: exynos-pmu: fix device leak on regmap lookup

      https://git.kernel.org/krzk/linux/c/990eb9a8eb4540ab90c7b34bb07b87ff13881cad

Best regards,

Signature · 1 line
Krzysztof Kozlowski <[email protected]>