Re: [PATCH] mmc: dw_mmc: Fix to avoid potential NULL pointer dereferenceãèææïéäçlinux-mmc-owner@xxxxxxxxxxxxxxxäåã

From: Shawn Lin
Date: Mon Mar 18 2019 - 20:43:20 EST


On 2019/3/19 8:19, Aditya Pakki wrote:
of_match_node can fail and return NULL in case no matching structure.
The patches checks for such a scenario and returns -ENXIO.

Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
---
drivers/mmc/host/dw_mmc-exynos.c | 2 ++
drivers/mmc/host/dw_mmc-k3.c | 2 ++
drivers/mmc/host/dw_mmc-pltfm.c | 2 ++
3 files changed, 6 insertions(+)


Could you check dw_mmc-zx.c and dw_mmc-rockchip.c as well?

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;
}