diff options
| author | Thomas Hellstrom <thellstrom@vmware.com> | 2012-01-24 21:54:21 +0400 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2012-01-25 13:27:45 +0400 |
| commit | 598781d71119827b454fd75d46f84755bca6f0c6 (patch) | |
| tree | 51ccb65b8e26b3347099af3f466ad0fedc6e1cb6 /drivers/gpu/drm/drm_fops.c | |
| parent | 15b63d35261ba3351d07e7937252f18bb6cbf814 (diff) | |
| download | linux-598781d71119827b454fd75d46f84755bca6f0c6.tar.xz | |
drm: Fix authentication kernel crash
If the master tries to authenticate a client using drm_authmagic and
that client has already closed its drm file descriptor,
either wilfully or because it was terminated, the
call to drm_authmagic will dereference a stale pointer into kmalloc'ed memory
and corrupt it.
Typically this results in a hard system hang.
This patch fixes that problem by removing any authentication tokens
(struct drm_magic_entry) open for a file descriptor when that file
descriptor is closed.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/drm_fops.c')
| -rw-r--r-- | drivers/gpu/drm/drm_fops.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index c00cf154cc0b..6263b0147598 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -487,6 +487,11 @@ int drm_release(struct inode *inode, struct file *filp) (long)old_encode_dev(file_priv->minor->device), dev->open_count); + /* Release any auth tokens that might point to this file_priv, + (do that under the drm_global_mutex) */ + if (file_priv->magic) + (void) drm_remove_magic(file_priv->master, file_priv->magic); + /* if the master has gone away we can't do anything with the lock */ if (file_priv->minor->master) drm_master_release(dev, filp); |