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PCI: pci-bridge-emul: Fix array overruns, improve safety

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We allow up to PCI_EXP_SLTSTA2 registers to be accessed, but the
pcie_cap_regs_behavior[] array only covers up to PCI_EXP_RTSTA.  Expand
this array to avoid walking off the end of it.

Do the same for pci_regs_behavior for consistency[], and add a
BUILD_BUG_ON() to also check the bridge->conf structure size.

Fixes: 23a5fba4d9 ("PCI: Introduce PCI bridge emulated config space common logic")
Link: https://lore.kernel.org/r/E1l6z9W-0006Re-MQ@rmk-PC.armlinux.org.uk
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
This commit is contained in:
Russell King 2021-02-02 17:07:46 +00:00 committed by Bjorn Helgaas
parent 508d392ae0
commit f8ee579d53
1 changed files with 8 additions and 3 deletions
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11
drivers/pci/pci-bridge-emul.c
View file

@ -21,8 +21,9 @@
#include "pci-bridge-emul.h"
#define PCI_BRIDGE_CONF_END PCI_STD_HEADER_SIZEOF
#define PCI_CAP_PCIE_SIZEOF (PCI_EXP_SLTSTA2 + 2)
#define PCI_CAP_PCIE_START PCI_BRIDGE_CONF_END
#define PCI_CAP_PCIE_END (PCI_CAP_PCIE_START + PCI_EXP_SLTSTA2 + 2)
#define PCI_CAP_PCIE_END (PCI_CAP_PCIE_START + PCI_CAP_PCIE_SIZEOF)
/**
* struct pci_bridge_reg_behavior - register bits behaviors
@ -46,7 +47,8 @@ struct pci_bridge_reg_behavior {
u32 w1c;
};
static const struct pci_bridge_reg_behavior pci_regs_behavior[] = {
static const
struct pci_bridge_reg_behavior pci_regs_behavior[PCI_STD_HEADER_SIZEOF / 4] = {
[PCI_VENDOR_ID / 4] = { .ro = ~0 },
[PCI_COMMAND / 4] = {
.rw = (PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
@ -164,7 +166,8 @@ static const struct pci_bridge_reg_behavior pci_regs_behavior[] = {
},
};
static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = {
static const
struct pci_bridge_reg_behavior pcie_cap_regs_behavior[PCI_CAP_PCIE_SIZEOF / 4] = {
[PCI_CAP_LIST_ID / 4] = {
/*
* Capability ID, Next Capability Pointer and
@ -260,6 +263,8 @@ static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = {
int pci_bridge_emul_init(struct pci_bridge_emul *bridge,
unsigned int flags)
{
BUILD_BUG_ON(sizeof(bridge->conf) != PCI_BRIDGE_CONF_END);
bridge->conf.class_revision |= cpu_to_le32(PCI_CLASS_BRIDGE_PCI << 16);
bridge->conf.header_type = PCI_HEADER_TYPE_BRIDGE;
bridge->conf.cache_line_size = 0x10;