Am Do., 27. Jan. 2022 um 23:29 Uhr schrieb Bjorn Helgaas <helgaas@xxxxxxxxxx>:
>
> On Mon, Jan 24, 2022 at 01:21:22PM +0100, Christian Gmeiner wrote:
> > This reverts commit 19e863828acf6d8ac8475ba1fd93c0fe17fdc4ef.
> >
> > Fixes the following oops:
> > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
>
> Hi Christian,
>
> Would you mind trying this patch?
>
Works - thanks. You can add my Tested-by.
> commit 9d36a93af8fe ("PCI: j721e: Initialize pcie->cdns_pcie before using it")
> Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Date: Thu Jan 27 15:49:49 2022 -0600
>
> 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
>
> Initialize pcie->cdns_pcie before it is used.
>
> Fixes: 19e863828acf ("PCI: j721e: Drop redundant struct device *")
> Reported-by: Christian Gmeiner <christian.gmeiner@xxxxxxxxx>
> Link: https://lore.kernel.org/r/20220124122132.435743-1-christian.gmeiner@xxxxxxxxx
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
> index 489586a4cdc7..5d950c1d9fd0 100644
> --- a/drivers/pci/controller/cadence/pci-j721e.c
> +++ b/drivers/pci/controller/cadence/pci-j721e.c
> @@ -372,10 +372,48 @@ static int j721e_pcie_probe(struct platform_device *pdev)
>
> mode = (u32)data->mode;
>
> + 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;
> + 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;
> + break;
> + default:
> + dev_err(dev, "INVALID device type %d\n", mode);
> + return 0;
> + }
> +
> + cdns_pcie->dev = dev;
> + cdns_pcie->ops = &j721e_pcie_ops;
> +
> pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> if (!pcie)
> return -ENOMEM;
>
> + pcie->cdns_pcie = cdns_pcie;
> pcie->mode = mode;
> pcie->linkdown_irq_regfield = data->linkdown_irq_regfield;
>
> @@ -426,28 +464,6 @@ 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 +513,6 @@ 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 +524,6 @@ 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;
--
greets
--
Christian Gmeiner, MSc
https://christian-gmeiner.info/privacypolicy
