6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Aleksandr Mishin amishin@t-argos.ru
[ Upstream commit a231707a91f323af1e5d9f1722055ec2fc1c7775 ]
If IORESOURCE_MEM is not provided in Device Tree due to any error, resource_list_first_type() will return NULL and pci_parse_request_of_pci_ranges() will just emit a warning.
This will cause a NULL pointer dereference. Fix this bug by adding NULL return check.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 0f71c60ffd26 ("PCI: dwc: Remove storing of PCI resources") Link: https://lore.kernel.org/linux-pci/20240505061517.11527-1-amishin@t-argos.ru Suggested-by: Bjorn Helgaas helgaas@kernel.org Suggested-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Aleksandr Mishin amishin@t-argos.ru Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/dwc/pci-keystone.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c index 9886fdd415039..54a3c7f29f78a 100644 --- a/drivers/pci/controller/dwc/pci-keystone.c +++ b/drivers/pci/controller/dwc/pci-keystone.c @@ -402,17 +402,22 @@ static const struct irq_domain_ops ks_pcie_legacy_irq_domain_ops = { .xlate = irq_domain_xlate_onetwocell, };
-static void ks_pcie_setup_rc_app_regs(struct keystone_pcie *ks_pcie) +static int ks_pcie_setup_rc_app_regs(struct keystone_pcie *ks_pcie) { u32 val; u32 num_viewport = ks_pcie->num_viewport; struct dw_pcie *pci = ks_pcie->pci; struct dw_pcie_rp *pp = &pci->pp; - u64 start, end; + struct resource_entry *entry; struct resource *mem; + u64 start, end; int i;
- mem = resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM)->res; + entry = resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM); + if (!entry) + return -ENODEV; + + mem = entry->res; start = mem->start; end = mem->end;
@@ -423,7 +428,7 @@ static void ks_pcie_setup_rc_app_regs(struct keystone_pcie *ks_pcie) ks_pcie_clear_dbi_mode(ks_pcie);
if (ks_pcie->is_am6) - return; + return 0;
val = ilog2(OB_WIN_SIZE); ks_pcie_app_writel(ks_pcie, OB_SIZE, val); @@ -440,6 +445,8 @@ static void ks_pcie_setup_rc_app_regs(struct keystone_pcie *ks_pcie) val = ks_pcie_app_readl(ks_pcie, CMD_STATUS); val |= OB_XLAT_EN_VAL; ks_pcie_app_writel(ks_pcie, CMD_STATUS, val); + + return 0; }
static void __iomem *ks_pcie_other_map_bus(struct pci_bus *bus, @@ -801,7 +808,10 @@ static int __init ks_pcie_host_init(struct dw_pcie_rp *pp) return ret;
ks_pcie_stop_link(pci); - ks_pcie_setup_rc_app_regs(ks_pcie); + ret = ks_pcie_setup_rc_app_regs(ks_pcie); + if (ret) + return ret; + writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8), pci->dbi_base + PCI_IO_BASE);