Unverified Commit 5089b3d8 authored by Zhongqiu Han's avatar Zhongqiu Han Committed by Krzysztof Wilczyński
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PCI: endpoint: epf-mhi: Avoid NULL dereference if DT lacks 'mmio' 

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: 1bf5f253 ("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: default avatarZhongqiu Han <quic_zhonhan@quicinc.com>
[kwilczynski: error message update per the review feedback]
Signed-off-by: default avatarKrzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: commit log]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarNiklas Cassel <cassel@kernel.org>
parent 9b80bdb1

drivers/pci/endpoint/functions/pci-epf-mhi.c

+6 −0
Original line number Diff line number Diff line
@@ -867,12 +867,18 @@ 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);