From c3d576baa6c8f0b34750a0b6f9b12e9d64625512 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 6 Jul 2023 15:37:51 +0300 Subject: [PATCH] dma-buf: fix an error pointer vs NULL bug MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 00ae1491f970acc454be0df63f50942d94825860 upstream. Smatch detected potential error pointer dereference. drivers/gpu/drm/drm_syncobj.c:888 drm_syncobj_transfer_to_timeline() error: 'fence' dereferencing possible ERR_PTR() The error pointer comes from dma_fence_allocate_private_stub(). One caller expected error pointers and one expected NULL pointers. Change it to return NULL and update the caller which expected error pointers, drm_syncobj_assign_null_handle(), to check for NULL instead. Fixes: f781f661e8c9 ("dma-buf: keep the signaling time of merged fences v3") Signed-off-by: Dan Carpenter Reviewed-by: Christian König Reviewed-by: Sumit Semwal Signed-off-by: Sumit Semwal Link: https://patchwork.freedesktop.org/patch/msgid/b09f1996-3838-4fa2-9193-832b68262e43@moroto.mountain Cc: Jindong Yue Signed-off-by: Greg Kroah-Hartman --- drivers/dma-buf/dma-fence.c | 2 +- drivers/gpu/drm/drm_syncobj.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 3855dc747fe5..eef4786aaf86 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -160,7 +160,7 @@ struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp) fence = kzalloc(sizeof(*fence), GFP_KERNEL); if (fence == NULL) - return ERR_PTR(-ENOMEM); + return NULL; dma_fence_init(fence, &dma_fence_stub_ops, diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 04589a35eb09..e592c5da70ce 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -355,8 +355,8 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj) { struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get()); - if (IS_ERR(fence)) - return PTR_ERR(fence); + if (!fence) + return -ENOMEM; drm_syncobj_replace_fence(syncobj, fence); dma_fence_put(fence);