[PATCH v2] phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug

[PATCH v2] phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug

[Chenyuan Yang]

The qmp_usb_iomap() helper function currently returns the raw result of
devm_ioremap() for non-exclusive mappings. Since devm_ioremap() may return
a NULL pointer and the caller only checks error pointers with IS_ERR(),
NULL could bypass the check and lead to an invalid dereference.

Fix the issue by checking if devm_ioremap() returns NULL. When it does,
qmp_usb_iomap() now returns an error pointer via IOMEM_ERR_PTR(-ENOMEM),
ensuring safe and consistent error handling.

Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
Fixes: a5d6b1ac56cb ("phy: qcom-qmp-usb: fix memleak on probe deferral")
CC: Johan Hovold <johan@kernel.org>
CC: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-usb.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-usb.c b/drivers/phy/qualcomm/phy-qcom-qmp-usb.c
index 787721570457..ed646a7e705b 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-usb.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-usb.c
@@ -2106,12 +2106,16 @@ static void __iomem *qmp_usb_iomap(struct device *dev, struct device_node *np,
 					int index, bool exclusive)
 {
 	struct resource res;
+	void __iomem *mem;
 
 	if (!exclusive) {
 		if (of_address_to_resource(np, index, &res))
 			return IOMEM_ERR_PTR(-EINVAL);
 
-		return devm_ioremap(dev, res.start, resource_size(&res));
+		mem = devm_ioremap(dev, res.start, resource_size(&res));
+		if (!mem)
+			return IOMEM_ERR_PTR(-ENOMEM);
+		return mem;
 	}
 
 	return devm_of_iomap(dev, np, index, NULL);
-- 
2.34.1

Re: [PATCH v2] phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug

[Johan Hovold]

On Mon, Apr 14, 2025 at 07:50:50AM -0500, Chenyuan Yang wrote:
> The qmp_usb_iomap() helper function currently returns the raw result of
> devm_ioremap() for non-exclusive mappings. Since devm_ioremap() may return
> a NULL pointer and the caller only checks error pointers with IS_ERR(),
> NULL could bypass the check and lead to an invalid dereference.
> 
> Fix the issue by checking if devm_ioremap() returns NULL. When it does,
> qmp_usb_iomap() now returns an error pointer via IOMEM_ERR_PTR(-ENOMEM),
> ensuring safe and consistent error handling.
> 
> Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
> Fixes: a5d6b1ac56cb ("phy: qcom-qmp-usb: fix memleak on probe deferral")
> CC: Johan Hovold <johan@kernel.org>
> CC: Krzysztof Kozlowski <krzk@kernel.org>
> ---

Thanks for the update, looks good.

Next time, remember to include a short changelog here after the --- line
(so that it does not get included in the commit message when the patch
is applied).

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>

Johan

Re: [PATCH v2] phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug

[Dmitry Baryshkov]

On Mon, Apr 14, 2025 at 07:50:50AM -0500, Chenyuan Yang wrote:
> The qmp_usb_iomap() helper function currently returns the raw result of
> devm_ioremap() for non-exclusive mappings. Since devm_ioremap() may return
> a NULL pointer and the caller only checks error pointers with IS_ERR(),
> NULL could bypass the check and lead to an invalid dereference.
> 
> Fix the issue by checking if devm_ioremap() returns NULL. When it does,
> qmp_usb_iomap() now returns an error pointer via IOMEM_ERR_PTR(-ENOMEM),
> ensuring safe and consistent error handling.
> 
> Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
> Fixes: a5d6b1ac56cb ("phy: qcom-qmp-usb: fix memleak on probe deferral")
> CC: Johan Hovold <johan@kernel.org>
> CC: Krzysztof Kozlowski <krzk@kernel.org>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-usb.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

-- 
With best wishes
Dmitry

Re: [PATCH v2] phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug

[Vinod Koul]

On Mon, 14 Apr 2025 07:50:50 -0500, Chenyuan Yang wrote:
> The qmp_usb_iomap() helper function currently returns the raw result of
> devm_ioremap() for non-exclusive mappings. Since devm_ioremap() may return
> a NULL pointer and the caller only checks error pointers with IS_ERR(),
> NULL could bypass the check and lead to an invalid dereference.
> 
> Fix the issue by checking if devm_ioremap() returns NULL. When it does,
> qmp_usb_iomap() now returns an error pointer via IOMEM_ERR_PTR(-ENOMEM),
> ensuring safe and consistent error handling.
> 
> [...]

Applied, thanks!

[1/1] phy: qcom-qmp-usb: Fix an NULL vs IS_ERR() bug
      commit: d14402a38c2d868cacb1facaf9be908ca6558e59

Best regards,
-- 
~Vinod