[PATCH 5.11 077/775] soc: qcom: ocmem: dont return NULL in of_get_ocmem

[Greg Kroah-Hartman]

From: Luca Weiss <l...@z3ntu.xyz>

[ Upstream commit 01f937ffc4686837d6c43dea80c6ade6cbd2940a ]

If ocmem probe fails for whatever reason, of_get_ocmem returned NULL.
Without this, users must check for both NULL and IS_ERR on the returned
pointer - which didn't happen in drivers/gpu/drm/msm/adreno/adreno_gpu.c
leading to a NULL pointer dereference.

Reviewed-by: Brian Masney <masn...@onstation.org>
Fixes: 88c1e9404f1d ("soc: qcom: add OCMEM driver")
Signed-off-by: Luca Weiss <l...@z3ntu.xyz>
Link: https://lore.kernel.org/r/20210130142349.53335-1-l...@z3ntu.xyz
Signed-off-by: Bjorn Andersson <bjorn.anders...@linaro.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/soc/qcom/ocmem.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/qcom/ocmem.c b/drivers/soc/qcom/ocmem.c
index 7f9e9944d1eae..f1875dc31ae2c 100644
--- a/drivers/soc/qcom/ocmem.c
+++ b/drivers/soc/qcom/ocmem.c
@@ -189,6 +189,7 @@ struct ocmem *of_get_ocmem(struct device *dev)
 {
        struct platform_device *pdev;
        struct device_node *devnode;
+       struct ocmem *ocmem;
 
        devnode = of_parse_phandle(dev->of_node, "sram", 0);
        if (!devnode || !devnode->parent) {
@@ -202,7 +203,12 @@ struct ocmem *of_get_ocmem(struct device *dev)
                return ERR_PTR(-EPROBE_DEFER);
        }
 
-       return platform_get_drvdata(pdev);
+       ocmem = platform_get_drvdata(pdev);
+       if (!ocmem) {
+               dev_err(dev, "Cannot get ocmem\n");
+               return ERR_PTR(-ENODEV);
+       }
+       return ocmem;
 }
 EXPORT_SYMBOL(of_get_ocmem);
 
-- 
2.27.0