6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Aleksandr Mishin <amishin@xxxxxxxxxx>
[ 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@xxxxxxxxxx
Suggested-by: Bjorn Helgaas <helgaas@xxxxxxxxxx>
Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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);
--
2.43.0
