PCI: of_property: Handle interrupt parsing failures

of_pci_prop_intr_map() uses uninitialized addr_sz[] values if
of_irq_parse_raw() fails, which leads to intermittent crashes.

Clear addr_sz[] before use so we never use uninitialized elements.

If no valid IRQs are parsed, don't bother adding the interrupt-map
property.

Fixes: 407d1a51921e ("PCI: Create device tree node for bridge")
Link: https://lore.kernel.org/r/1696007448-42127-1-git-send-email-lizhi.hou@amd.com
Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Closes: https://lore.kernel.org/all/20230911154856.000076c3@Huawei.com/
Reported-by: Herve Codina <herve.codina@bootlin.com>
Closes: https://lore.kernel.org/all/20230911171319.495bb837@bootlin.com/
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
[bhelgaas: commit log, add similar report from Herve]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Herve Codina <herve.codina@bootlin.com>

diff --git a/drivers/pci/of_property.c b/drivers/pci/of_property.c
index 710ec35ba4a17738906f0e1aad105b702e288e2d..c2c7334152bc0522c9a8ec2a4d44e66ffae344e8 100644 (file)
--- a/drivers/pci/of_property.c
+++ b/drivers/pci/of_property.c
@@ -186,8 +186,8 @@ static int of_pci_prop_interrupts(struct pci_dev *pdev,
 static int of_pci_prop_intr_map(struct pci_dev *pdev, struct of_changeset *ocs,
                                struct device_node *np)
 {
+       u32 i, addr_sz[OF_PCI_MAX_INT_PIN] = { 0 }, map_sz = 0;
        struct of_phandle_args out_irq[OF_PCI_MAX_INT_PIN];
-       u32 i, addr_sz[OF_PCI_MAX_INT_PIN], map_sz = 0;
        __be32 laddr[OF_PCI_ADDRESS_CELLS] = { 0 };
        u32 int_map_mask[] = { 0xffff00, 0, 0, 7 };
        struct device_node *pnode;
@@ -213,33 +213,44 @@ static int of_pci_prop_intr_map(struct pci_dev *pdev, struct of_changeset *ocs,
                out_irq[i].args[0] = pin;
                ret = of_irq_parse_raw(laddr, &out_irq[i]);
                if (ret) {
-                       pci_err(pdev, "parse irq %d failed, ret %d", pin, ret);
+                       out_irq[i].np = NULL;
+                       pci_dbg(pdev, "parse irq %d failed, ret %d", pin, ret);
                        continue;
                }
-               ret = of_property_read_u32(out_irq[i].np, "#address-cells",
-                                          &addr_sz[i]);
-               if (ret)
-                       addr_sz[i] = 0;
+               of_property_read_u32(out_irq[i].np, "#address-cells",
+                                    &addr_sz[i]);
        }
 
        list_for_each_entry(child, &pdev->subordinate->devices, bus_list) {
                for (pin = 1; pin <= OF_PCI_MAX_INT_PIN; pin++) {
                        i = pci_swizzle_interrupt_pin(child, pin) - 1;
+                       if (!out_irq[i].np)
+                               continue;
                        map_sz += 5 + addr_sz[i] + out_irq[i].args_count;
                }
        }
 
+       /*
+        * Parsing interrupt failed for all pins. In this case, it does not
+        * need to generate interrupt-map property.
+        */
+       if (!map_sz)
+               return 0;
+
        int_map = kcalloc(map_sz, sizeof(u32), GFP_KERNEL);
        mapp = int_map;
 
        list_for_each_entry(child, &pdev->subordinate->devices, bus_list) {
                for (pin = 1; pin <= OF_PCI_MAX_INT_PIN; pin++) {
+                       i = pci_swizzle_interrupt_pin(child, pin) - 1;
+                       if (!out_irq[i].np)
+                               continue;
+
                        *mapp = (child->bus->number << 16) |
                                (child->devfn << 8);
                        mapp += OF_PCI_ADDRESS_CELLS;
                        *mapp = pin;
                        mapp++;
-                       i = pci_swizzle_interrupt_pin(child, pin) - 1;
                        *mapp = out_irq[i].np->phandle;
                        mapp++;
                        if (addr_sz[i]) {