From 053ca37c87af65f41f5842070c68aa53c3d035f5 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 27 Jan 2022 15:49:49 -0600 Subject: [PATCH] PCI: j721e: Initialize pcie->cdns_pcie before using it Christian reported a NULL pointer dereference in j721e_pcie_probe() caused by 19e863828acf ("PCI: j721e: Drop redundant struct device *"), which removed struct j721e_pcie.dev since there's another copy in struct cdns_pcie.dev reachable via j721e_pcie->cdns_pcie->dev. The problem is that j721e_pcie->cdns_pcie was dereferenced before being initialized: j721e_pcie_probe pcie = devm_kzalloc() # struct j721e_pcie j721e_pcie_ctrl_init(pcie) dev = pcie->cdns_pcie->dev <-- dereference cdns_pcie switch (mode) { case PCI_MODE_RC: cdns_pcie = ... # alloc as part of pci_host_bridge pcie->cdns_pcie = cdns_pcie <-- initialize pcie->cdns_pcie Move the cdns_pcie initialization earlier so it is done before it is used. This also simplifies the error exits. Fixes: 19e863828acf ("PCI: j721e: Drop redundant struct device *") Link: https://lore.kernel.org/r/20220127222951.GA144828@bhelgaas Link: https://lore.kernel.org/r/20220124122132.435743-1-christian.gmeiner@gmail.com Reported-by: Christian Gmeiner Tested-by: Christian Gmeiner Signed-off-by: Bjorn Helgaas --- drivers/pci/controller/cadence/pci-j721e.c | 85 +++++++++++----------- 1 file changed, 42 insertions(+), 43 deletions(-) diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c index 489586a4cdc7..768d33f9ebc8 100644 --- a/drivers/pci/controller/cadence/pci-j721e.c +++ b/drivers/pci/controller/cadence/pci-j721e.c @@ -356,8 +356,8 @@ static int j721e_pcie_probe(struct platform_device *pdev) const struct j721e_pcie_data *data; struct cdns_pcie *cdns_pcie; struct j721e_pcie *pcie; - struct cdns_pcie_rc *rc; - struct cdns_pcie_ep *ep; + struct cdns_pcie_rc *rc = NULL; + struct cdns_pcie_ep *ep = NULL; struct gpio_desc *gpiod; void __iomem *base; struct clk *clk; @@ -376,6 +376,46 @@ static int j721e_pcie_probe(struct platform_device *pdev) if (!pcie) return -ENOMEM; + switch (mode) { + case PCI_MODE_RC: + if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)) + return -ENODEV; + + bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc)); + if (!bridge) + return -ENOMEM; + + if (!data->byte_access_allowed) + bridge->ops = &cdns_ti_pcie_host_ops; + rc = pci_host_bridge_priv(bridge); + rc->quirk_retrain_flag = data->quirk_retrain_flag; + rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag; + + cdns_pcie = &rc->pcie; + cdns_pcie->dev = dev; + cdns_pcie->ops = &j721e_pcie_ops; + pcie->cdns_pcie = cdns_pcie; + break; + case PCI_MODE_EP: + if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP)) + return -ENODEV; + + ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL); + if (!ep) + return -ENOMEM; + + ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag; + + cdns_pcie = &ep->pcie; + cdns_pcie->dev = dev; + cdns_pcie->ops = &j721e_pcie_ops; + pcie->cdns_pcie = cdns_pcie; + break; + default: + dev_err(dev, "INVALID device type %d\n", mode); + return 0; + } + pcie->mode = mode; pcie->linkdown_irq_regfield = data->linkdown_irq_regfield; @@ -426,28 +466,6 @@ static int j721e_pcie_probe(struct platform_device *pdev) switch (mode) { case PCI_MODE_RC: - if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)) { - ret = -ENODEV; - goto err_get_sync; - } - - bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc)); - if (!bridge) { - ret = -ENOMEM; - goto err_get_sync; - } - - if (!data->byte_access_allowed) - bridge->ops = &cdns_ti_pcie_host_ops; - rc = pci_host_bridge_priv(bridge); - rc->quirk_retrain_flag = data->quirk_retrain_flag; - rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag; - - cdns_pcie = &rc->pcie; - cdns_pcie->dev = dev; - cdns_pcie->ops = &j721e_pcie_ops; - pcie->cdns_pcie = cdns_pcie; - gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); if (IS_ERR(gpiod)) { ret = PTR_ERR(gpiod); @@ -497,23 +515,6 @@ static int j721e_pcie_probe(struct platform_device *pdev) break; case PCI_MODE_EP: - if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP)) { - ret = -ENODEV; - goto err_get_sync; - } - - ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL); - if (!ep) { - ret = -ENOMEM; - goto err_get_sync; - } - ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag; - - cdns_pcie = &ep->pcie; - cdns_pcie->dev = dev; - cdns_pcie->ops = &j721e_pcie_ops; - pcie->cdns_pcie = cdns_pcie; - ret = cdns_pcie_init_phy(dev, cdns_pcie); if (ret) { dev_err(dev, "Failed to init phy\n"); @@ -525,8 +526,6 @@ static int j721e_pcie_probe(struct platform_device *pdev) goto err_pcie_setup; break; - default: - dev_err(dev, "INVALID device type %d\n", mode); } return 0; -- GitLab