From 0bc1c2d4a7e8f9ee47c8bd1e92a2adf00ffceb12 Mon Sep 17 00:00:00 2001 From: Zhang Changzhong Date: Tue, 8 Dec 2020 09:54:32 +0800 Subject: [PATCH] slimbus: qcom: fix potential NULL dereference in qcom_slim_prg_slew() [ Upstream commit 428bb001143cf5bfb65aa4ae90d4ebc95f82d007 ] platform_get_resource_byname() may fail and in this case a NULL dereference will occur. Fix it to use devm_platform_ioremap_resource_byname() instead of calling platform_get_resource_byname() and devm_ioremap(). This is detected by Coccinelle semantic patch. @@ expression pdev, res, n, t, e, e1, e2; @@ res = \(platform_get_resource\|platform_get_resource_byname\)(pdev, t, n); + if (!res) + return -EINVAL; ... when != res == NULL e = devm_ioremap(e1, res->start, e2); Fixes: ad7fcbc308b0 ("slimbus: qcom: Add Qualcomm Slimbus controller driver") Signed-off-by: Zhang Changzhong Link: https://lore.kernel.org/r/1607392473-20610-1-git-send-email-zhangchangzhong@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/slimbus/qcom-ctrl.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/slimbus/qcom-ctrl.c b/drivers/slimbus/qcom-ctrl.c index 4aad2566f52d2..f04b961b96cd4 100644 --- a/drivers/slimbus/qcom-ctrl.c +++ b/drivers/slimbus/qcom-ctrl.c @@ -472,15 +472,10 @@ static void qcom_slim_rxwq(struct work_struct *work) static void qcom_slim_prg_slew(struct platform_device *pdev, struct qcom_slim_ctrl *ctrl) { - struct resource *slew_mem; - if (!ctrl->slew_reg) { /* SLEW RATE register for this SLIMbus */ - slew_mem = platform_get_resource_byname(pdev, IORESOURCE_MEM, - "slew"); - ctrl->slew_reg = devm_ioremap(&pdev->dev, slew_mem->start, - resource_size(slew_mem)); - if (!ctrl->slew_reg) + ctrl->slew_reg = devm_platform_ioremap_resource_byname(pdev, "slew"); + if (IS_ERR(ctrl->slew_reg)) return; }