[patch v2] vfio/pci: make an array larger

2015-11-09 Thread Dan Carpenter
Smatch complains about a possible out of bounds error:

drivers/vfio/pci/vfio_pci_config.c:1241 vfio_cap_init()
error: buffer overflow 'pci_cap_length' 20 <= 20

The problem is that pci_cap_length[] was defined as large enough to
hold "PCI_CAP_ID_AF + 1" elements.  The code in vfio_cap_init() assumes
it has PCI_CAP_ID_MAX + 1 elements.  Originally, PCI_CAP_ID_AF and
PCI_CAP_ID_MAX were the same but then we introduced PCI_CAP_ID_EA in
f80b0ba95964 ('PCI: Add Enhanced Allocation register entries') so now
the array is too small.

Let's fix this by making the array size PCI_CAP_ID_MAX + 1.  And let's
make a similar change to pci_ext_cap_length[] for consistency.  Also
both these arrays can be made const.

Signed-off-by: Dan Carpenter 
---
v2: more cleanups

diff --git a/drivers/vfio/pci/vfio_pci_config.c 
b/drivers/vfio/pci/vfio_pci_config.c
index a8657ef..fe2b470 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -46,7 +46,7 @@
  *   0: Removed from the user visible capability list
  *   FF: Variable length
  */
-static u8 pci_cap_length[] = {
+static const u8 pci_cap_length[PCI_CAP_ID_MAX + 1] = {
[PCI_CAP_ID_BASIC]  = PCI_STD_HEADER_SIZEOF, /* pci config header */
[PCI_CAP_ID_PM] = PCI_PM_SIZEOF,
[PCI_CAP_ID_AGP]= PCI_AGP_SIZEOF,
@@ -74,7 +74,7 @@ static u8 pci_cap_length[] = {
  *   0: Removed or masked from the user visible capabilty list
  *   FF: Variable length
  */
-static u16 pci_ext_cap_length[] = {
+static const u16 pci_ext_cap_length[PCI_EXT_CAP_ID_MAX + 1] = {
[PCI_EXT_CAP_ID_ERR]=   PCI_ERR_ROOT_COMMAND,
[PCI_EXT_CAP_ID_VC] =   0xFF,
[PCI_EXT_CAP_ID_DSN]=   PCI_EXT_CAP_DSN_SIZEOF,
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html


Re: [patch v2] vfio/pci: make an array larger

2015-11-10 Thread Alex Williamson
On Mon, 2015-11-09 at 15:24 +0300, Dan Carpenter wrote:
> Smatch complains about a possible out of bounds error:
> 
>   drivers/vfio/pci/vfio_pci_config.c:1241 vfio_cap_init()
>   error: buffer overflow 'pci_cap_length' 20 <= 20
> 
> The problem is that pci_cap_length[] was defined as large enough to
> hold "PCI_CAP_ID_AF + 1" elements.  The code in vfio_cap_init() assumes
> it has PCI_CAP_ID_MAX + 1 elements.  Originally, PCI_CAP_ID_AF and
> PCI_CAP_ID_MAX were the same but then we introduced PCI_CAP_ID_EA in
> f80b0ba95964 ('PCI: Add Enhanced Allocation register entries') so now
> the array is too small.
> 
> Let's fix this by making the array size PCI_CAP_ID_MAX + 1.  And let's
> make a similar change to pci_ext_cap_length[] for consistency.  Also
> both these arrays can be made const.
> 
> Signed-off-by: Dan Carpenter 
> ---

Applied to next for v4.4.  Thanks!

Alex

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html