[PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()

From: Geert Uytterhoeven
Date: Tue Aug 04 2020 - 08:30:26 EST

The conversion to modern host bridge probing made the driver allocate
its private data using devm_pci_alloc_host_bridge(), but forgot to
remove the old allocation. Hence part of the driver initialization is
done using the new instance, while another part is done using the old
instance, leading to a crash due to uninitialized bridge DMA ranges:

Unable to handle kernel NULL pointer dereference at virtual address 00000008
pgd = (ptrval)
[00000008] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
PC is at rcar_pci_probe+0x154/0x340
LR is at _raw_spin_unlock_irqrestore+0x18/0x20

Fix this by dropping the old allocation.

Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
drivers/pci/controller/pci-rcar-gen2.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/pci/controller/pci-rcar-gen2.c b/drivers/pci/controller/pci-rcar-gen2.c
index 046965d284a6d54e..c9530038ca9a53fc 100644
--- a/drivers/pci/controller/pci-rcar-gen2.c
+++ b/drivers/pci/controller/pci-rcar-gen2.c
@@ -302,10 +302,6 @@ static int rcar_pci_probe(struct platform_device *pdev)
if (mem_res->start & 0xFFFF)
return -EINVAL;

- priv = devm_kzalloc(dev, sizeof(struct rcar_pci_priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
priv->mem_res = *mem_res;
priv->cfg_res = cfg_res;