From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sun, 13 May 2012 17:09:38 +0000 (+0300)
Subject: iommu: Fix off by one in dmar_get_fault_reason()
X-Git-Tag: v3.3.8~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4f4e3f10fb3427bfafd2e3439124000f2874c457;p=thirdparty%2Fkernel%2Fstable.git

iommu: Fix off by one in dmar_get_fault_reason()

commit fefe1ed1398b81e3fadc92d11d91162d343c8836 upstream.

fault_reason - 0x20 == ARRAY_SIZE(irq_remap_fault_reasons) is
one past the end of the array.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Youquan Song <youquan.song@intel.com>
Cc: walter harms <wharms@bfs.de>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/20120513170938.GA4280@elgon.mountain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2: s/irq_remap_fault_reasons/intr_remap_fault_reasons/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 35c1e17fce1d0..97b2e21ac46ac 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1056,8 +1056,8 @@ static const char *intr_remap_fault_reasons[] =
 
 const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
 {
-	if (fault_reason >= 0x20 && (fault_reason <= 0x20 +
-				     ARRAY_SIZE(intr_remap_fault_reasons))) {
+	if (fault_reason >= 0x20 && (fault_reason - 0x20 <
+					ARRAY_SIZE(intr_remap_fault_reasons))) {
 		*fault_type = INTR_REMAP;
 		return intr_remap_fault_reasons[fault_reason - 0x20];
 	} else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {