drm/nouveau: Validate channel indices passed from userspace.

When hacking the libdrm for improvements, I triggered a kernel crash
related to the fact that the NOUVEAU_NOTIFIEROBJ_ALLOC ioctl calls
nouveau_channel_get with an unchecked channel index.
The patch ensures that the channel index is an unsigned and validates
its value in nouveau_channel_get.

Signed-off-by: Michel Hermier <hermier@frugalware.org>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Michel Hermier 2010-12-25 16:58:56 +01:00 committed by Ben Skeggs
parent c42988012a
commit 8e91182bbd

View file

@ -253,6 +253,9 @@ nouveau_channel_get(struct drm_device *dev, struct drm_file *file_priv, int id)
struct nouveau_channel *chan;
unsigned long flags;
if (unlikely(id < 0 || id >= NOUVEAU_MAX_CHANNEL_NR))
return ERR_PTR(-EINVAL);
spin_lock_irqsave(&dev_priv->channels.lock, flags);
chan = nouveau_channel_get_unlocked(dev_priv->channels.ptr[id]);
spin_unlock_irqrestore(&dev_priv->channels.lock, flags);