diff options
| author |   Sean Paul <seanpaul@chromium.org> | 2018-05-31 14:48:58 -0400 |
|---|---|---|
| committer |   Rob Clark <robdclark@gmail.com> | 2018-06-04 12:50:42 -0400 |
| commit | 74d3a3a70775de356b96b5461c3a204a51496fb3 (patch) | |
| tree | 40705c1662d17f938b5a9991d3524fcd6b03f8db /drivers/gpu | |
| parent | drm/msm: Switch to atomic_helper_commit() (diff) | |
| download | linux-dev-74d3a3a70775de356b96b5461c3a204a51496fb3.tar.xz linux-dev-74d3a3a70775de356b96b5461c3a204a51496fb3.zip | |
drm/msm: Fix NULL deref on bind/probe deferral
This patch avoids dereferencing msm_host->dev when it is NULL.
If we find ourselves tearing down dsi before calling
(mdp4|mdp5|dpu)_kms_init(), we'll end up in a state where the dev
pointer is NULL and trying to extract priv from it will fail.
This was introduced in a seemingly innocuous commit to ensure the
arguments to msm_gem_put_iova() are correct (even though that
function has been a stub for ~5 years). Correctness FTW! \o/
Fixes: b01884a286b0 drm/msm: use correct aspace pointer in msm_gem_put_iova()
Cc: Daniel Mack <daniel@zonque.org>
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/msm/dsi/dsi_host.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index b916f464f4ec..2f1a2780658a 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1066,8 +1066,18 @@ static int dsi_tx_buf_alloc(struct msm_dsi_host *msm_host, int size) static void dsi_tx_buf_free(struct msm_dsi_host *msm_host) { struct drm_device *dev = msm_host->dev; - struct msm_drm_private *priv = dev->dev_private; + struct msm_drm_private *priv; + + /* + * This is possible if we're tearing down before we've had a chance to + * fully initialize. A very real possibility if our probe is deferred, + * in which case we'll hit msm_dsi_host_destroy() without having run + * through the dsi_tx_buf_alloc(). + */ + if (!dev) + return; + priv = dev->dev_private; if (msm_host->tx_gem_obj) { msm_gem_put_iova(msm_host->tx_gem_obj, priv->kms->aspace); drm_gem_object_put_unlocked(msm_host->tx_gem_obj); |