On 2023-10-03 19:29, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
> array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct amdgpu_bo_list.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> Cc: Alex Deucher <alexander.deuc...@amd.com>
> Cc: "Christian König" <christian.koe...@amd.com>
> Cc: "Pan, Xinhui" <xinhui....@amd.com>
> Cc: David Airlie <airl...@gmail.com>
> Cc: Daniel Vetter <dan...@ffwll.ch>
> Cc: "Gustavo A. R. Silva" <gustavo...@kernel.org>
> Cc: Luben Tuikov <luben.tui...@amd.com>
> Cc: Christophe JAILLET <christophe.jail...@wanadoo.fr>
> Cc: Felix Kuehling <felix.kuehl...@amd.com>
> Cc: amd-...@lists.freedesktop.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: linux-harden...@vger.kernel.org
> Link:
> https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> [1]
> Signed-off-by: Kees Cook <keesc...@chromium.org>
Reviewed-by: Luben Tuikov <luben.tui...@amd.com>
--
Regards,
Luben
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 2 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
> index 6f5b641b631e..781e5c5ce04d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
> @@ -84,6 +84,7 @@ int amdgpu_bo_list_create(struct amdgpu_device *adev,
> struct drm_file *filp,
>
> kref_init(&list->refcount);
>
> + list->num_entries = num_entries;
> array = list->entries;
>
> for (i = 0; i < num_entries; ++i) {
> @@ -129,7 +130,6 @@ int amdgpu_bo_list_create(struct amdgpu_device *adev,
> struct drm_file *filp,
> }
>
> list->first_userptr = first_userptr;
> - list->num_entries = num_entries;
> sort(array, last_entry, sizeof(struct amdgpu_bo_list_entry),
> amdgpu_bo_list_entry_cmp, NULL);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
> index 6a703be45d04..555cd6d877c3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
> @@ -56,7 +56,7 @@ struct amdgpu_bo_list {
> */
> struct mutex bo_list_mutex;
>
> - struct amdgpu_bo_list_entry entries[];
> + struct amdgpu_bo_list_entry entries[] __counted_by(num_entries);
> };
>
> int amdgpu_bo_list_get(struct amdgpu_fpriv *fpriv, int id,
