5.15-stable review patch. If anyone has any objections, please let me know.
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From: Aleksandr Mishin amishin@t-argos.ru
[ 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@t-argos.ru Suggested-by: Bjorn Helgaas helgaas@kernel.org Signed-off-by: Aleksandr Mishin amishin@t-argos.ru Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 e8afa50129a8..60a0d59a533f 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 pcie_port *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 pcie_port *pp) @@ -305,7 +313,9 @@ static int al_pcie_host_init(struct pcie_port *pp) if (rc) return rc;
- al_pcie_config_prepare(pcie); + rc = al_pcie_config_prepare(pcie); + if (rc) + return rc;
return 0; }