Re: [PATCH V1] accel/amdxdna: Remove __counted_by from struct amdxdna_cmd_chain

Max Zhen <[email protected]>
Newsgroups org.freedesktop.lists.dri-devel,org.kernel.vger.linux-kernel
Message-ID <[email protected]>

On 8/20/2026 Thu 20:35, Lizhi Hou wrote:
> struct amdxdna_cmd_chain contains a flexible array annotated with
> __counted_by(command_count). Since the structure is stored in shared
> AMDXDNA_BO_SHARE memory, userspace can modify command_count concurrently.
> If command_count is changed to zero, the bounds check generated from
> __counted_by may fail and trigger a kernel panic.
> 
> Remove __counted_by to avoid relying on the userspace-controlled
> command_count for the flexible array bounds check.
> 
> Fixes: aac243092b70 ("accel/amdxdna: Add command execution")
> Signed-off-by: Lizhi Hou <[email protected]>
Reviewed-by: Max Zhen <[email protected]>
> ---
>   drivers/accel/amdxdna/amdxdna_ctx.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/accel/amdxdna/amdxdna_ctx.h b/drivers/accel/amdxdna/amdxdna_ctx.h
> index e6155f4b5db0..010538cb05a3 100644
> --- a/drivers/accel/amdxdna/amdxdna_ctx.h
> +++ b/drivers/accel/amdxdna/amdxdna_ctx.h
> @@ -56,7 +56,7 @@ struct amdxdna_cmd_chain {
>   	u32 submit_index;
>   	u32 error_index;
>   	u32 reserved[3];
> -	u64 data[] __counted_by(command_count);
> +	u64 data[];
>   };
>   
>   /*
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.