Re: [PATCH] net: ethernet: mediatek: add NULL check on of_match_device() return value
From: Andrew Lunn <andrew@lunn.ch>
Date: 2017-07-07 14:57:24
Also in:
linux-arm-kernel, linux-mediatek, lkml
On Fri, Jul 07, 2017 at 02:11:35AM -0500, Gustavo A. R. Silva wrote:
quoted hunk ↗ jump to hunk
Check return value from call to of_match_device() in order to prevent a NULL pointer dereference. In case of NULL print error message and return -ENODEV Signed-off-by: Gustavo A. R. Silva <redacted> --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index adaaafc..6a77dea 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c@@ -2408,6 +2408,11 @@ static int mtk_probe(struct platform_device *pdev) int i; match = of_match_device(of_mtk_match, &pdev->dev); + if (!match) { + dev_err(&pdev->dev, "failed to match device\n"); + return -ENODEV; + } + soc = (struct mtk_soc_data *)match->data;
Hi Gustavo
I think you are fixing the wrong thing. The soc variable is unused. Also,
const struct of_device_id of_mtk_match[] = {
{ .compatible = "mediatek,mt2701-eth" },
{},
};
So match->data is NULL. This code is all pointless and should be
removed, rather than try to avoid a NULL pointer dereference which can
not actually happen.
Andrew