From: Jan Niehusmann <jan@gondor.com>
Date: Mon, 6 Jun 2016 14:20:11 +0200
Subject: iommu/vt-d: Fix overflow of iommu->domains array
Git-commit: 3bd4f9112f87a9c65fe6e817272806167f0bc9ed
Patch-mainline: v4.7-rc6
References: fate#321026

The valid range of 'did' in get_iommu_domain(*iommu, did)
is 0..cap_ndoms(iommu->cap), so don't exceed that
range in free_all_cpu_cached_iovas().

The user-visible impact of the out-of-bounds access is the machine
hanging on suspend-to-ram. It is, in fact, a kernel panic, but due
to already suspended devices, that's often not visible to the user.

Fixes: 22e2f9fa63b0 ("iommu/vt-d: Use per-cpu IOVA caching")
Signed-off-by: Jan Niehusmann <jan@gondor.com>
Tested-By: Marius Vlad <marius.c.vlad@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/intel-iommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4678,7 +4678,7 @@ static void free_all_cpu_cached_iovas(un
 		if (!iommu)
 			continue;
 
-		for (did = 0; did < 0xffff; did++) {
+		for (did = 0; did < cap_ndoms(iommu->cap); did++) {
 			domain = get_iommu_domain(iommu, did);
 
 			if (!domain)
