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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Alex Williamson <alex.williamson@redhat.com>,
	"Sean O. Stalley" <sean.stalley@intel.com>
Cc: Mark Rustad <mark.d.rustad@intel.com>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [patch v2] vfio/pci: make an array larger
Date: Mon, 09 Nov 2015 12:24:55 +0000	[thread overview]
Message-ID: <20151109122455.GA28870@mwanda> (raw)
In-Reply-To: <1446661738.3692.129.camel@redhat.com>

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 <dan.carpenter@oracle.com>
---
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,

  reply	other threads:[~2015-11-09 12:24 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-04 13:26 [patch] vfio: make an array larger Dan Carpenter
2015-11-04 16:40 ` Joe Perches
2015-11-04 18:23   ` Dan Carpenter
2015-11-04 16:54 ` Alex Williamson
2015-11-04 18:20   ` Dan Carpenter
2015-11-04 18:28     ` Alex Williamson
2015-11-09 12:24       ` Dan Carpenter [this message]
2015-11-10 19:03         ` [patch v2] vfio/pci: " Alex Williamson
2015-11-04 21:39 ` [patch] vfio: " walter harms

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