From 43e86c8f5b6d9f6279e20dede4e1f7829bdc43b7 Mon Sep 17 00:00:00 2001
From: Isaku Yamahata <yamahata@valinux.co.jp>
Date: Fri, 29 Jul 2011 10:01:43 +0900
Subject: [PATCH] pcie_host: verify mmcfg address range
For a conventional pci device behind
a pcie-to-pci bridge, pci_host handlers get confused by
an out of bounds access in the range [256, 4K).
Check for such an access and make it have no effect.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
hw/pcie_host.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
diff --git a/hw/pcie_host.c b/hw/pcie_host.c
index f0b3d13aae..f9fea3d918 100644
--- a/hw/pcie_host.c
+++ b/hw/pcie_host.c
@@ -56,23 +56,39 @@ static void pcie_mmcfg_data_write(PCIBus *s,
uint32_t mmcfg_addr, uint32_t val, int len)
{
PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
+ uint32_t addr;
+ uint32_t limit;
if (!pci_dev) {
return;
}
- pci_host_config_write_common(pci_dev, PCIE_MMCFG_CONFOFFSET(mmcfg_addr),
- pci_config_size(pci_dev), val, len);
+ addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
+ limit = pci_config_size(pci_dev);
+ if (limit <= addr) {
+ /* conventional pci device can be behind pcie-to-pci bridge.
+ 256 <= addr < 4K has no effects. */
+ return;
+ }
+ pci_host_config_write_common(pci_dev, addr, limit, val, len);
}
-static uint32_t pcie_mmcfg_data_read(PCIBus *s, uint32_t addr, int len)
+static uint32_t pcie_mmcfg_data_read(PCIBus *s, uint32_t mmcfg_addr, int len)
{
- PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, addr);
+ PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr);
+ uint32_t addr;
+ uint32_t limit;
if (!pci_dev) {
return ~0x0;
}
- return pci_host_config_read_common(pci_dev, PCIE_MMCFG_CONFOFFSET(addr),
- pci_config_size(pci_dev), len);
+ addr = PCIE_MMCFG_CONFOFFSET(mmcfg_addr);
+ limit = pci_config_size(pci_dev);
+ if (limit <= addr) {
+ /* conventional pci device can be behind pcie-to-pci bridge.
+ 256 <= addr < 4K has no effects. */
+ return ~0x0;
+ }
+ return pci_host_config_read_common(pci_dev, addr, limit, len);
}
static void pcie_mmcfg_data_writeb(void *opaque,
--
2.30.2