Hi, > -----Original Message----- > From: Min Li <lm0963hack@xxxxxxxxx> > Sent: Friday, May 26, 2023 10:02 PM > To: inki.dae@xxxxxxxxxxx > Cc: sw0312.kim@xxxxxxxxxxx; kyungmin.park@xxxxxxxxxxx; airlied@xxxxxxxxx; > daniel@xxxxxxxx; krzysztof.kozlowski@xxxxxxxxxx; alim.akhtar@xxxxxxxxxxx; > dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > linux-samsung-soc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: [PATCH] drm/exynos: fix race condition UAF in > exynos_g2d_exec_ioctl > > If it is async, runqueue_node is freed in g2d_runqueue_worker on another > worker thread. So in extreme cases, if g2d_runqueue_worker runs first, and > then executes the following if statement, there will be use-after-free. > I received a report about the related issue from a white hacker before. Thanks for contribution. :) > Signed-off-by: Min Li <lm0963hack@xxxxxxxxx> > --- > drivers/gpu/drm/exynos/exynos_drm_g2d.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c > b/drivers/gpu/drm/exynos/exynos_drm_g2d.c > index ec784e58da5c..414e585ec7dd 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c > @@ -1335,7 +1335,7 @@ int exynos_g2d_exec_ioctl(struct drm_device *drm_dev, > void *data, > /* Let the runqueue know that there is work to do. */ > queue_work(g2d->g2d_workq, &g2d->runqueue_work); > > - if (runqueue_node->async) > + if (req->async) > goto out; > > wait_for_completion(&runqueue_node->complete); > -- > 2.34.1
