From 0caa7616a6aca449dd68b58cb29bd491d296c2d5 Mon Sep 17 00:00:00 2001 From: Aaron Campbell Date: Sat, 2 Jul 2016 21:23:24 -0300 Subject: [PATCH] iommu/vt-d: Fix infinite loop in free_all_cpu_cached_iovas Per VT-d spec Section 10.4.2 ("Capability Register"), the maximum number of possible domains is 64K; indeed this is the maximum value that the cap_ndoms() macro will expand to. Since the value 65536 will not fix in a u16, the 'did' variable must be promoted to an int, otherwise the test for < 65536 will always be true and the loop will never end. The symptom, in my case, was a hung machine during suspend. Fixes: 3bd4f9112f87 ("iommu/vt-d: Fix overflow of iommu->domains array") Signed-off-by: Aaron Campbell Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index cfe410eedaf0..323dac9900ba 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4602,13 +4602,13 @@ static void free_all_cpu_cached_iovas(unsigned int cpu) for (i = 0; i < g_num_of_iommus; i++) { struct intel_iommu *iommu = g_iommus[i]; struct dmar_domain *domain; - u16 did; + int did; if (!iommu) continue; for (did = 0; did < cap_ndoms(iommu->cap); did++) { - domain = get_iommu_domain(iommu, did); + domain = get_iommu_domain(iommu, (u16)did); if (!domain) continue; -- 2.20.1