[PATCH 6.1 61/71] usb: dwc3: st: fix probed platform device ref count on probe error path

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

commit ddfcfeba891064b88bb844208b43bef2ef970f0c upstream.

The probe function never performs any paltform device allocation, thus
error path "undo_platform_dev_alloc" is entirely bogus.  It drops the
reference count from the platform device being probed.  If error path is
triggered, this will lead to unbalanced device reference counts and
premature release of device resources, thus possible use-after-free when
releasing remaining devm-managed resources.

Fixes: f83fca0707c6 ("usb: dwc3: add ST dwc3 glue layer to manage dwc3 HC")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20240814093957.37940-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/dwc3/dwc3-st.c |   11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

--- a/drivers/usb/dwc3/dwc3-st.c
+++ b/drivers/usb/dwc3/dwc3-st.c
@@ -219,10 +219,8 @@ static int st_dwc3_probe(struct platform
 	dwc3_data->regmap = regmap;
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-reg");
-	if (!res) {
-		ret = -ENXIO;
-		goto undo_platform_dev_alloc;
-	}
+	if (!res)
+		return -ENXIO;
 
 	dwc3_data->syscfg_reg_off = res->start;
 
@@ -233,8 +231,7 @@ static int st_dwc3_probe(struct platform
 		devm_reset_control_get_exclusive(dev, "powerdown");
 	if (IS_ERR(dwc3_data->rstc_pwrdn)) {
 		dev_err(&pdev->dev, "could not get power controller\n");
-		ret = PTR_ERR(dwc3_data->rstc_pwrdn);
-		goto undo_platform_dev_alloc;
+		return PTR_ERR(dwc3_data->rstc_pwrdn);
 	}
 
 	/* Manage PowerDown */
@@ -300,8 +297,6 @@ undo_softreset:
 	reset_control_assert(dwc3_data->rstc_rst);
 undo_powerdown:
 	reset_control_assert(dwc3_data->rstc_pwrdn);
-undo_platform_dev_alloc:
-	platform_device_put(pdev);
 	return ret;
 }