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drm/shmem-helper: Remove another errant put in error path

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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>
This commit is contained in:
Dmitry Osipenko 2023-01-09 00:13:11 +03:00 committed by Greg Kroah-Hartman
parent fbc5ffcce7
commit 684c7372bb
1 changed files with 6 additions and 3 deletions
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9
drivers/gpu/drm/drm_gem_shmem_helper.c
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@ -614,11 +614,14 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
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);
return dma_buf_mmap(obj->dma_buf, vma, 0);
/* Drop the reference drm_gem_mmap_obj() acquired.*/
if (!ret)
drm_gem_object_put(obj);
return ret;
}
shmem = to_drm_gem_shmem_obj(obj);