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authorDmitry Osipenko <dmitry.osipenko@collabora.com>2023-01-09 00:13:11 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-22 15:38:03 +0300
commit77d26c824aa5a7e0681ef1d5b75fe538d746addc (patch)
tree44e9aaa93e62fa941b0f102e96cf13705d7e9a4f
parent598c42c78919117dc0d235ae22d17ad642377483 (diff)
downloadlinux-77d26c824aa5a7e0681ef1d5b75fe538d746addc.tar.xz
drm/shmem-helper: Remove another errant put in error path
commit ee9adb7a45516cfa536ca92253d7ae59d56db9e4 upstream. drm_gem_shmem_mmap() doesn't own reference in error code path, resulting in the dma-buf shmem GEM object getting prematurely freed leading to a later use-after-free. Fixes: f49a51bfdc8e ("drm/shme-helpers: Fix dma_buf_mmap forwarding bug") Cc: stable@vger.kernel.org Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Reviewed-by: Rob Clark <robdclark@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230108211311.3950107-1-dmitry.osipenko@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/drm_gem_shmem_helper.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 7af9da886d4e..5fdc608043e7 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -622,11 +622,14 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
int ret;
if (obj->import_attach) {
- /* Drop the reference drm_gem_mmap_obj() acquired.*/
- drm_gem_object_put(obj);
vma->vm_private_data = NULL;
+ ret = dma_buf_mmap(obj->dma_buf, vma, 0);
+
+ /* Drop the reference drm_gem_mmap_obj() acquired.*/
+ if (!ret)
+ drm_gem_object_put(obj);
- return dma_buf_mmap(obj->dma_buf, vma, 0);
+ return ret;
}
ret = drm_gem_shmem_get_pages(shmem);