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authorLinus Torvalds <torvalds@linux-foundation.org>2015-12-18 12:38:35 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-12-18 12:38:35 -0800
commitccdd96be43a2e27fc69152df8fcfd30f2902b255 (patch)
tree1cb10bc7a358fabf15df6ed4153e1cb0bfa69e07
parent3273cba1956437820ae25d98e3ae57d1c094205c (diff)
parent7f8312a3b31de5676144d9e75f2f2647c8b4b769 (diff)
downloadlinux-ccdd96be43a2e27fc69152df8fcfd30f2902b255.tar.bz2
Merge tag 'iommu-fixes-v4.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU fixes from Joerg Roedel: "Two similar fixes for the Intel and AMD IOMMU drivers to add proper access checks before calling handle_mm_fault" * tag 'iommu-fixes-v4.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/vt-d: Do access checks before calling handle_mm_fault() iommu/amd: Do proper access checking before calling handle_mm_fault()
-rw-r--r--drivers/iommu/amd_iommu_v2.c20
-rw-r--r--drivers/iommu/intel-svm.c20
2 files changed, 38 insertions, 2 deletions
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index d21d4edf7236..7caf2fa237f2 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -494,6 +494,22 @@ static void handle_fault_error(struct fault *fault)
}
}
+static bool access_error(struct vm_area_struct *vma, struct fault *fault)
+{
+ unsigned long requested = 0;
+
+ if (fault->flags & PPR_FAULT_EXEC)
+ requested |= VM_EXEC;
+
+ if (fault->flags & PPR_FAULT_READ)
+ requested |= VM_READ;
+
+ if (fault->flags & PPR_FAULT_WRITE)
+ requested |= VM_WRITE;
+
+ return (requested & ~vma->vm_flags) != 0;
+}
+
static void do_fault(struct work_struct *work)
{
struct fault *fault = container_of(work, struct fault, work);
@@ -516,8 +532,8 @@ static void do_fault(struct work_struct *work)
goto out;
}
- if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) {
- /* handle_mm_fault would BUG_ON() */
+ /* Check if we have the right permissions on the vma */
+ if (access_error(vma, fault)) {
up_read(&mm->mmap_sem);
handle_fault_error(fault);
goto out;
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index c69e3f9ec958..50464833d0b8 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -484,6 +484,23 @@ struct page_req_dsc {
};
#define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x10)
+
+static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req)
+{
+ unsigned long requested = 0;
+
+ if (req->exe_req)
+ requested |= VM_EXEC;
+
+ if (req->rd_req)
+ requested |= VM_READ;
+
+ if (req->wr_req)
+ requested |= VM_WRITE;
+
+ return (requested & ~vma->vm_flags) != 0;
+}
+
static irqreturn_t prq_event_thread(int irq, void *d)
{
struct intel_iommu *iommu = d;
@@ -539,6 +556,9 @@ static irqreturn_t prq_event_thread(int irq, void *d)
if (!vma || address < vma->vm_start)
goto invalid;
+ if (access_error(vma, req))
+ goto invalid;
+
ret = handle_mm_fault(svm->mm, vma, address,
req->wr_req ? FAULT_FLAG_WRITE : 0);
if (ret & VM_FAULT_ERROR)