[PATCH v2] mmc: dw_mmc: Fix to avoid potential NULL pointer dereference

[Aditya Pakki]

of_match_node can fail and return NULL in case no matching structure.
The patches checks for such a scenario and returns -ENXIO.

---
V1: Added files dw_mmc-zx.c and dw_mmc-rockchip.c

Signed-off-by: Aditya Pakki <pakki...@umn.edu>
---
 drivers/mmc/host/dw_mmc-exynos.c   | 2 ++
 drivers/mmc/host/dw_mmc-k3.c       | 2 ++
 drivers/mmc/host/dw_mmc-pltfm.c    | 2 ++
 drivers/mmc/host/dw_mmc-rockchip.c | 2 ++
 drivers/mmc/host/dw_mmc-zx.c       | 2 ++
 5 files changed, 10 insertions(+)

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index d46c3439b508..8a75d7314606 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -554,6 +554,8 @@ static int dw_mci_exynos_probe(struct platform_device *pdev)
        int ret;
 
        match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
+       if (!match)
+               return -ENXIO;
        drv_data = match->data;
 
        pm_runtime_get_noresume(&pdev->dev);
diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
index 89cdb3d533bb..cc50b7546a20 100644
--- a/drivers/mmc/host/dw_mmc-k3.c
+++ b/drivers/mmc/host/dw_mmc-k3.c
@@ -459,6 +459,8 @@ static int dw_mci_k3_probe(struct platform_device *pdev)
        const struct of_device_id *match;
 
        match = of_match_node(dw_mci_k3_match, pdev->dev.of_node);
+       if (!match)
+               return -ENXIO;
        drv_data = match->data;
 
        return dw_mci_pltfm_register(pdev, drv_data);
diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
index 58c13e21bd5a..b1948989f617 100644
--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -82,6 +82,8 @@ static int dw_mci_pltfm_probe(struct platform_device *pdev)
 
        if (pdev->dev.of_node) {
                match = of_match_node(dw_mci_pltfm_match, pdev->dev.of_node);
+               if (!match)
+                       return -ENXIO;
                drv_data = match->data;
        }
 
diff --git a/drivers/mmc/host/dw_mmc-rockchip.c 
b/drivers/mmc/host/dw_mmc-rockchip.c
index 8c86a800a8fd..20e3471260ea 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -344,6 +344,8 @@ static int dw_mci_rockchip_probe(struct platform_device 
*pdev)
                return -ENODEV;
 
        match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node);
+       if (!match)
+               return -ENXIO;
        drv_data = match->data;
 
        pm_runtime_get_noresume(&pdev->dev);
diff --git a/drivers/mmc/host/dw_mmc-zx.c b/drivers/mmc/host/dw_mmc-zx.c
index c06b5393312f..abea35431045 100644
--- a/drivers/mmc/host/dw_mmc-zx.c
+++ b/drivers/mmc/host/dw_mmc-zx.c
@@ -213,6 +213,8 @@ static int dw_mci_zx_probe(struct platform_device *pdev)
        const struct of_device_id *match;
 
        match = of_match_node(dw_mci_zx_match, pdev->dev.of_node);
+       if (!match)
+               return -ENXIO;
        drv_data = match->data;
 
        return dw_mci_pltfm_register(pdev, drv_data);
-- 
2.17.1