From: Aleksandr Mishin <amishin@xxxxxxxxxx> [ Upstream commit a9927c2cac6e9831361e43a14d91277818154e6a ] If IORESOURCE_BUS is not provided in Device Tree it will be fabricated in of_pci_parse_bus_range(), so NULL pointer dereference should not happen here. But that's hard to verify, so check for NULL anyway. Found by Linux Verification Center (linuxtesting.org) with SVACE. Link: https://lore.kernel.org/linux-pci/20240503125705.46055-1-amishin@xxxxxxxxxx Suggested-by: Bjorn Helgaas <helgaas@xxxxxxxxxx> Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx> Signed-off-by: Krzysztof Wilczyński <kwilczynski@xxxxxxxxxx> [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/pci/controller/dwc/pcie-al.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-al.c b/drivers/pci/controller/dwc/pcie-al.c index b8cb77c9c4bd2..3132b27bc0064 100644 --- a/drivers/pci/controller/dwc/pcie-al.c +++ b/drivers/pci/controller/dwc/pcie-al.c @@ -242,18 +242,24 @@ static struct pci_ops al_child_pci_ops = { .write = pci_generic_config_write, }; -static void al_pcie_config_prepare(struct al_pcie *pcie) +static int al_pcie_config_prepare(struct al_pcie *pcie) { struct al_pcie_target_bus_cfg *target_bus_cfg; struct dw_pcie_rp *pp = &pcie->pci->pp; unsigned int ecam_bus_mask; + struct resource_entry *ft; u32 cfg_control_offset; + struct resource *bus; u8 subordinate_bus; u8 secondary_bus; u32 cfg_control; u32 reg; - struct resource *bus = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS)->res; + ft = resource_list_first_type(&pp->bridge->windows, IORESOURCE_BUS); + if (!ft) + return -ENODEV; + + bus = ft->res; target_bus_cfg = &pcie->target_bus_cfg; ecam_bus_mask = (pcie->ecam_size >> PCIE_ECAM_BUS_SHIFT) - 1; @@ -287,6 +293,8 @@ static void al_pcie_config_prepare(struct al_pcie *pcie) FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus); al_pcie_controller_writel(pcie, cfg_control_offset, reg); + + return 0; } static int al_pcie_host_init(struct dw_pcie_rp *pp) @@ -305,7 +313,9 @@ static int al_pcie_host_init(struct dw_pcie_rp *pp) if (rc) return rc; - al_pcie_config_prepare(pcie); + rc = al_pcie_config_prepare(pcie); + if (rc) + return rc; return 0; } -- 2.43.0
