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authorJuergen Gross <jgross@suse.com>2017-10-25 17:08:07 +0200
committerBoris Ostrovsky <boris.ostrovsky@oracle.com>2017-10-25 12:48:13 -0400
commit298d275d4d9bea3524ff4bc76678c140611d8a8d (patch)
tree4337329fdc85462328edb08a35f6c373c82ab6f1 /drivers/xen
parente1043a4bb9fce6cfc7d55c5767e429a18ac8c4eb (diff)
downloadlinux-298d275d4d9bea3524ff4bc76678c140611d8a8d.tar.bz2
xen/gntdev: avoid out of bounds access in case of partial gntdev_mmap()
In case gntdev_mmap() succeeds only partially in mapping grant pages it will leave some vital information uninitialized needed later for cleanup. This will lead to an out of bounds array access when unmapping the already mapped pages. So just initialize the data needed for unmapping the pages a little bit earlier. Cc: <stable@vger.kernel.org> Reported-by: Arthur Borsboom <arthurborsboom@gmail.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/gntdev.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 82360594fa8e..57efbd3b053b 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -1024,6 +1024,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
mutex_unlock(&priv->lock);
if (use_ptemod) {
+ map->pages_vm_start = vma->vm_start;
err = apply_to_page_range(vma->vm_mm, vma->vm_start,
vma->vm_end - vma->vm_start,
find_grant_ptes, map);
@@ -1061,7 +1062,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
set_grant_ptes_as_special, NULL);
}
#endif
- map->pages_vm_start = vma->vm_start;
}
return 0;