From fc87e919c0ce8e213edf2ffca17f384f059873d3 Mon Sep 17 00:00:00 2001 From: Kenji Kaneshige Date: Wed, 19 Aug 2009 10:58:46 +0900 Subject: [PATCH] PCI ASPM: fix possible null pointer dereference Fix possible NULL dereference in pcie_aspm_exit_link_state(). This patch also cleanup some code. Acked-by: Shaohua Li Signed-off-by: Kenji Kaneshige Signed-off-by: Jesse Barnes --- drivers/pci/pcie/aspm.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 638881b00f6..0800c514682 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -665,16 +665,16 @@ out: void pcie_aspm_exit_link_state(struct pci_dev *pdev) { struct pci_dev *parent = pdev->bus->self; - struct pcie_link_state *link_state = parent->link_state; + struct pcie_link_state *link; - if (aspm_disabled || !pdev->is_pcie || !parent || !link_state) + if (aspm_disabled || !pdev->is_pcie || !parent || !parent->link_state) return; if (parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT && - parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM) + parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM) return; + down_read(&pci_bus_sem); mutex_lock(&aspm_lock); - /* * All PCIe functions are in one slot, remove one function will remove * the whole slot, so just wait until we are the last function left. @@ -682,13 +682,14 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) if (!list_is_last(&pdev->bus_list, &parent->subordinate->devices)) goto out; + link = parent->link_state; + /* All functions are removed, so just disable ASPM for the link */ __pcie_aspm_config_one_dev(parent, 0); - list_del(&link_state->sibling); - list_del(&link_state->link); + list_del(&link->sibling); + list_del(&link->link); /* Clock PM is for endpoint device */ - - free_link_state(link_state); + free_link_state(link); out: mutex_unlock(&aspm_lock); up_read(&pci_bus_sem); -- 2.20.1