It will cause null-ptr-deref in resource_size(), if platform_get_resource() returns NULL, move calling resource_size() after devm_ioremap_resource() that will check 'res' to avoid null-ptr-deref. And use devm_platform_get_and_ioremap_resource() to simplify code. Fixes: b3fdd32799d8 ("i2c: mux: Add register-based mux i2c-mux-reg") Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> --- The previous link: https://lore.kernel.org/lkml/20220425090509.2524814-1-yangyingliang@xxxxxxxxxx/ --- drivers/i2c/muxes/i2c-mux-reg.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/muxes/i2c-mux-reg.c b/drivers/i2c/muxes/i2c-mux-reg.c index 0e0679f65cf7..30a6de1694e0 100644 --- a/drivers/i2c/muxes/i2c-mux-reg.c +++ b/drivers/i2c/muxes/i2c-mux-reg.c @@ -183,13 +183,12 @@ static int i2c_mux_reg_probe(struct platform_device *pdev) if (!mux->data.reg) { dev_info(&pdev->dev, "Register not set, using platform resource\n"); - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - mux->data.reg_size = resource_size(res); - mux->data.reg = devm_ioremap_resource(&pdev->dev, res); + mux->data.reg = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(mux->data.reg)) { ret = PTR_ERR(mux->data.reg); goto err_put_parent; } + mux->data.reg_size = resource_size(res); } if (mux->data.reg_size != 4 && mux->data.reg_size != 2 && -- 2.25.1