From: Johan Hovold Date: Tue, 13 Sep 2022 08:53:11 +0000 (+0200) Subject: drm/msm: fix use-after-free on probe deferral X-Git-Tag: v6.0.7~174 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0a30a47741b6df1f9555a0fac6aebb7e8c363bad;p=thirdparty%2Fkernel%2Fstable.git drm/msm: fix use-after-free on probe deferral commit 6808abdb33bf90330e70a687d29f038507e06ebb upstream. The bridge counter was never reset when tearing down the DRM device so that stale pointers to deallocated structures would be accessed on the next tear down (e.g. after a second late bind deferral). Given enough bridges and a few probe deferrals this could currently also lead to data beyond the bridge array being corrupted. Fixes: d28ea556267c ("drm/msm: properly add and remove internal bridges") Fixes: a3376e3ec81c ("drm/msm: convert to drm_bridge") Cc: stable@vger.kernel.org # 3.12 Reviewed-by: Dmitry Baryshkov Signed-off-by: Johan Hovold Tested-by: Kuogee Hsieh Reviewed-by: Kuogee Hsieh Patchwork: https://patchwork.freedesktop.org/patch/502665/ Link: https://lore.kernel.org/r/20220913085320.8577-2-johan+linaro@kernel.org Signed-off-by: Abhinav Kumar Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index 0759e2d99f59c..869ba58f02544 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -241,6 +241,7 @@ static int msm_drm_uninit(struct device *dev) for (i = 0; i < priv->num_bridges; i++) drm_bridge_remove(priv->bridges[i]); + priv->num_bridges = 0; pm_runtime_get_sync(dev); msm_irq_uninstall(ddev);