https://bugzilla.kernel.org/show_bug.cgi?id=94361 reported NULL Pointer in pcie_aspm_init_link_state(), Some platform like ATCA may has strange PCIe topology: E.g. ---root port---downstream port---upstream port |--downstream port |--downstream port When we try to alloc pcie_link_state, we assumed downstream port always has a upstream port, in this case, NULL pointer would be triggered when try to find the parent pci_link_state, because downstream port connects to root port directly. Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx> --- drivers/pci/pcie/aspm.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 7d4fcdc..f295824 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -526,8 +526,17 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) INIT_LIST_HEAD(&link->link); link->pdev = pdev; if (pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM) { - struct pcie_link_state *parent; - parent = pdev->bus->parent->self->link_state; + struct pci_bus *pbus = pdev->bus; + struct pcie_link_state *parent = NULL; + + while (pbus) { + if (pbus->self) { + parent = pbus->self->link_state; + if (parent) + break; + } + pbus = pbus->parent; + } if (!parent) { kfree(link); return NULL; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
