From 2f98735c9c24ea1f0d40a364d4e63611b689b795 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sat, 2 Feb 2008 03:08:53 +0100 Subject: vm audit: add VM_DONTEXPAND to mmap for drivers that need it Drivers that register a ->fault handler, but do not range-check the offset argument, must set VM_DONTEXPAND in the vm_flags in order to prevent an expanding mremap from overflowing the resource. I've audited the tree and attempted to fix these problems (usually by adding VM_DONTEXPAND where it is not obvious). Signed-off-by: Nick Piggin Signed-off-by: Linus Torvalds --- drivers/char/drm/drm_vm.c | 2 ++ drivers/char/mspec.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/char/drm/drm_vm.c b/drivers/char/drm/drm_vm.c index e8d50af58201..ef5e6b130c48 100644 --- a/drivers/char/drm/drm_vm.c +++ b/drivers/char/drm/drm_vm.c @@ -506,6 +506,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma) vma->vm_ops = &drm_vm_dma_ops; vma->vm_flags |= VM_RESERVED; /* Don't swap */ + vma->vm_flags |= VM_DONTEXPAND; vma->vm_file = filp; /* Needed for drm_vm_open() */ drm_vm_open_locked(vma); @@ -655,6 +656,7 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) return -EINVAL; /* This should never happen. */ } vma->vm_flags |= VM_RESERVED; /* Don't swap */ + vma->vm_flags |= VM_DONTEXPAND; vma->vm_file = filp; /* Needed for drm_vm_open() */ drm_vm_open_locked(vma); diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c index 82f2e27dca7d..ff146c2b08fd 100644 --- a/drivers/char/mspec.c +++ b/drivers/char/mspec.c @@ -283,7 +283,7 @@ mspec_mmap(struct file *file, struct vm_area_struct *vma, vdata->refcnt = ATOMIC_INIT(1); vma->vm_private_data = vdata; - vma->vm_flags |= (VM_IO | VM_RESERVED | VM_PFNMAP); + vma->vm_flags |= (VM_IO | VM_RESERVED | VM_PFNMAP | VM_DONTEXPAND); if (vdata->type == MSPEC_FETCHOP || vdata->type == MSPEC_UNCACHED) vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); vma->vm_ops = &mspec_vm_ops; -- cgit v1.2.2