From f2e62a69087e2d0d6e91168d27368edbf0d0e059 Mon Sep 17 00:00:00 2001 From: Zhongqiu Han Date: Tue, 5 Nov 2024 20:07:35 +0800 Subject: [PATCH] PCI: endpoint: epf-mhi: Avoid NULL dereference if DT lacks 'mmio' MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 5089b3d874e9933d9842e90410d3af1520494757 ] If platform_get_resource_byname() fails and returns NULL because DT lacks an 'mmio' property for the MHI endpoint, dereferencing res->start will cause a NULL pointer access. Add a check to prevent it. Fixes: 1bf5f25324f7 ("PCI: endpoint: Add PCI Endpoint function driver for MHI bus") Link: https://lore.kernel.org/r/20241105120735.1240728-1-quic_zhonhan@quicinc.com Signed-off-by: Zhongqiu Han [kwilczynski: error message update per the review feedback] Signed-off-by: Krzysztof Wilczyński [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas Reviewed-by: Niklas Cassel Signed-off-by: Sasha Levin --- drivers/pci/endpoint/functions/pci-epf-mhi.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c index 34e7191f950867..87154992ea11b9 100644 --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c @@ -600,12 +600,18 @@ static int pci_epf_mhi_bind(struct pci_epf *epf) { struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf); struct pci_epc *epc = epf->epc; + struct device *dev = &epf->dev; struct platform_device *pdev = to_platform_device(epc->dev.parent); struct resource *res; int ret; /* Get MMIO base address from Endpoint controller */ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio"); + if (!res) { + dev_err(dev, "Failed to get \"mmio\" resource\n"); + return -ENODEV; + } + epf_mhi->mmio_phys = res->start; epf_mhi->mmio_size = resource_size(res);