diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-4.19/950-0486-drm-v3d-Fix-a-use-after-free-race-accessing-the-sche.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-4.19/950-0486-drm-v3d-Fix-a-use-after-free-race-accessing-the-sche.patch | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-4.19/950-0486-drm-v3d-Fix-a-use-after-free-race-accessing-the-sche.patch b/target/linux/bcm27xx/patches-4.19/950-0486-drm-v3d-Fix-a-use-after-free-race-accessing-the-sche.patch new file mode 100644 index 0000000000..126452f974 --- /dev/null +++ b/target/linux/bcm27xx/patches-4.19/950-0486-drm-v3d-Fix-a-use-after-free-race-accessing-the-sche.patch @@ -0,0 +1,73 @@ +From f5f3df2b1746a9ba9420ae11988fc37a7b93691d Mon Sep 17 00:00:00 2001 +From: Eric Anholt <eric@anholt.net> +Date: Fri, 28 Sep 2018 16:21:23 -0700 +Subject: [PATCH] drm/v3d: Fix a use-after-free race accessing the + scheduler's fences. + +Once we push the job, the scheduler could run it and free it. So, if +we want to reference their fences, we need to grab them before then. +I haven't seen this happen in many days of conformance test runtime, +but let's still close the race. + +Signed-off-by: Eric Anholt <eric@anholt.net> +Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+") +Link: https://patchwork.freedesktop.org/patch/254119/ +Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com> +(cherry picked from commit 34c2c4f632f232ed2fdb66d4e42cc72d322273fe) +--- + drivers/gpu/drm/v3d/v3d_drv.h | 5 +++++ + drivers/gpu/drm/v3d/v3d_gem.c | 8 ++++++-- + 2 files changed, 11 insertions(+), 2 deletions(-) + +--- a/drivers/gpu/drm/v3d/v3d_drv.h ++++ b/drivers/gpu/drm/v3d/v3d_drv.h +@@ -198,6 +198,11 @@ struct v3d_exec_info { + */ + struct dma_fence *bin_done_fence; + ++ /* Fence for when the scheduler considers the render to be ++ * done, for when the BOs reservations should be complete. ++ */ ++ struct dma_fence *render_done_fence; ++ + struct kref refcount; + + /* This is the array of BOs that were looked up at the start of exec. */ +--- a/drivers/gpu/drm/v3d/v3d_gem.c ++++ b/drivers/gpu/drm/v3d/v3d_gem.c +@@ -209,7 +209,7 @@ v3d_flush_caches(struct v3d_dev *v3d) + static void + v3d_attach_object_fences(struct v3d_exec_info *exec) + { +- struct dma_fence *out_fence = &exec->render.base.s_fence->finished; ++ struct dma_fence *out_fence = exec->render_done_fence; + struct v3d_bo *bo; + int i; + +@@ -409,6 +409,7 @@ v3d_exec_cleanup(struct kref *ref) + dma_fence_put(exec->render.done_fence); + + dma_fence_put(exec->bin_done_fence); ++ dma_fence_put(exec->render_done_fence); + + for (i = 0; i < exec->bo_count; i++) + drm_gem_object_put_unlocked(&exec->bo[i]->base); +@@ -572,6 +573,9 @@ v3d_submit_cl_ioctl(struct drm_device *d + if (ret) + goto fail_unreserve; + ++ exec->render_done_fence = ++ dma_fence_get(&exec->render.base.s_fence->finished); ++ + kref_get(&exec->refcount); /* put by scheduler job completion */ + drm_sched_entity_push_job(&exec->render.base, + &v3d_priv->sched_entity[V3D_RENDER]); +@@ -585,7 +589,7 @@ v3d_submit_cl_ioctl(struct drm_device *d + sync_out = drm_syncobj_find(file_priv, args->out_sync); + if (sync_out) { + drm_syncobj_replace_fence(sync_out, +- &exec->render.base.s_fence->finished); ++ exec->render_done_fence); + drm_syncobj_put(sync_out); + } + |