[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@xxxxxxxxx>
Fixes: a5d6b1ac56cb ("phy: qcom-qmp-usb: fix memleak on probe deferral")
CC: Johan Hovold <johan@xxxxxxxxxx>
CC: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
---
 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