Commit 7f8312a3 authored by Joerg Roedel's avatar Joerg Roedel

iommu/vt-d: Do access checks before calling handle_mm_fault()

Not doing so is a bug and might trigger a BUG_ON in
handle_mm_fault(). So add the proper permission checks
before calling into mm code.
Reviewed-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Acked-By: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 7b5cc1a9
...@@ -484,6 +484,23 @@ struct page_req_dsc { ...@@ -484,6 +484,23 @@ struct page_req_dsc {
}; };
#define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x10) #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) static irqreturn_t prq_event_thread(int irq, void *d)
{ {
struct intel_iommu *iommu = d; struct intel_iommu *iommu = d;
...@@ -539,6 +556,9 @@ static irqreturn_t prq_event_thread(int irq, void *d) ...@@ -539,6 +556,9 @@ static irqreturn_t prq_event_thread(int irq, void *d)
if (!vma || address < vma->vm_start) if (!vma || address < vma->vm_start)
goto invalid; goto invalid;
if (access_error(vma, req))
goto invalid;
ret = handle_mm_fault(svm->mm, vma, address, ret = handle_mm_fault(svm->mm, vma, address,
req->wr_req ? FAULT_FLAG_WRITE : 0); req->wr_req ? FAULT_FLAG_WRITE : 0);
if (ret & VM_FAULT_ERROR) if (ret & VM_FAULT_ERROR)
......
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