Re: [PATCH] media: cobalt: fix null-ptr-deref when there is no PCI bridge
From: Hans Verkuil <hidden>
Date: 2021-05-05 09:18:30
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On 24/04/2021 02:52, Tong Zhang wrote:
the PCI bridge might be NULL, so we'd better check before use it [ 1.870569] RIP: 0010:pcie_bus_link_get_lanes.isra.0+0x26/0x59 [cobalt] [ 1.875880] Call Trace: [ 1.876013] cobalt_probe.cold+0x1be/0xc11 [cobalt] [ 1.876683] pci_device_probe+0x10f/0x1c0
How did you test this? With some virtualized PCI bus or something? I'm not sure how this can happen. Regards, Hans
quoted hunk ↗ jump to hunk
Signed-off-by: Tong Zhang <redacted> --- drivers/media/pci/cobalt/cobalt-driver.c | 4 ++++ 1 file changed, 4 insertions(+)diff --git a/drivers/media/pci/cobalt/cobalt-driver.c b/drivers/media/pci/cobalt/cobalt-driver.c index 0695078ef812..5687ed4869ac 100644 --- a/drivers/media/pci/cobalt/cobalt-driver.c +++ b/drivers/media/pci/cobalt/cobalt-driver.c@@ -189,6 +189,8 @@ void cobalt_pcie_status_show(struct cobalt *cobalt) u32 capa; u16 stat, ctrl; + if (!pci_bus_dev) + return; if (!pci_is_pcie(pci_dev) || !pci_is_pcie(pci_bus_dev)) return;@@ -247,6 +249,8 @@ static unsigned pcie_bus_link_get_lanes(struct cobalt *cobalt) struct pci_dev *pci_dev = cobalt->pci_dev->bus->self; u32 link; + if (!pci_dev) + return 0; if (!pci_is_pcie(pci_dev)) return 0; pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &link);