diff options
Diffstat (limited to 'drivers/xen/gntdev.c')
| -rw-r--r-- | drivers/xen/gntdev.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 2c4cc940c42..2a4733c621c 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -294,7 +294,9 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) if (pgno >= offset && pgno < offset + pages && use_ptemod) { void __user *tmp; tmp = map->vma->vm_start + map->notify.addr; - copy_to_user(tmp, &err, 1); + err = copy_to_user(tmp, &err, 1); + if (err) + return err; map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; } else if (pgno >= offset && pgno < offset + pages) { uint8_t *tmp = kmap(map->pages[pgno]); @@ -599,6 +601,12 @@ static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) goto unlock_out; found: + if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && + (map->flags & GNTMAP_readonly)) { + rc = -EINVAL; + goto unlock_out; + } + map->notify.flags = op.action; map->notify.addr = op.index - (map->index << PAGE_SHIFT); map->notify.event = op.event_channel_port; |