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authorNick Piggin <npiggin@suse.de>2008-02-02 03:08:53 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2008-02-04 07:55:38 -0800
commit2f98735c9c24ea1f0d40a364d4e63611b689b795 (patch)
treea42b3802449af474d36cda3b6f9fb190a717defb /drivers/char
parentfe2528b96b02173395f5a75e37714c07f3e25e73 (diff)
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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 <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/drm/drm_vm.c2
-rw-r--r--drivers/char/mspec.c2
2 files changed, 3 insertions, 1 deletions
diff --git a/drivers/char/drm/drm_vm.c b/drivers/char/drm/drm_vm.c
index e8d50af..ef5e6b1 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 82f2e27..ff146c2 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;