This is a note to let you know that I've just added the patch titled
PCI: pci-bridge-emul: Fix array overruns, improve safety
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-pci-bridge-emul-fix-array-overruns-improve-safet.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 484ded3b33d5f4d386f77febf522d072fc371e0f
Author: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Date: Tue Feb 2 17:07:46 2021 +0000
PCI: pci-bridge-emul: Fix array overruns, improve safety
[ Upstream commit f8ee579d53aca887d93f5f411462f25c085a5106 ]
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: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Link: https://lore.kernel.org/r/E1l6z9W-0006Re-MQ@xxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Pali Rohár <pali@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c
index 139869d50eb26..fdaf86a888b73 100644
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -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;
