From patchwork Tue Mar 7 16:58:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 13164303 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32786C678D5 for ; Tue, 7 Mar 2023 17:50:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232249AbjCGRul (ORCPT ); Tue, 7 Mar 2023 12:50:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232252AbjCGRuR (ORCPT ); Tue, 7 Mar 2023 12:50:17 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9893D9CFFD; Tue, 7 Mar 2023 09:45:08 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3E3DAB819BF; Tue, 7 Mar 2023 17:45:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6FF0C433EF; Tue, 7 Mar 2023 17:45:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678211107; bh=a30CykW6YykybRzJUgVbj82sbmewX3xLsAzMmIApp0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Lnq6eexuC/1lYjbrbFBGgU5ET9slJNY1aVY0jqSFvtpw9sZaI4078N+G5m0o2icxM QoxxB6CXwEgJcPb98RvC5SJJf6J5AUH2yq1KbG7pguZ6WcHJlmDPw7zwFhiJ1h3+Fk xiHDipz0uYWszdbTvqCDxWJfU84A2v4A/MPXjLYg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe , Pavel Begunkov , "Gustavo A. R. Silva" , io-uring@vger.kernel.org, Kees Cook Subject: [PATCH 6.2 0754/1001] io_uring: Replace 0-length array with flexible array Date: Tue, 7 Mar 2023 17:58:46 +0100 Message-Id: <20230307170054.429075050@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org From: Kees Cook commit 36632d062975a9ff4410c90dd6d37922b68d0920 upstream. Zero-length arrays are deprecated[1]. Replace struct io_uring_buf_ring's "bufs" with a flexible array member. (How is the size of this array verified?) Detected with GCC 13, using -fstrict-flex-arrays=3: In function 'io_ring_buffer_select', inlined from 'io_buffer_select' at io_uring/kbuf.c:183:10: io_uring/kbuf.c:141:23: warning: array subscript 255 is outside the bounds of an interior zero-length array 'struct io_uring_buf[0]' [-Wzero-length-bounds] 141 | buf = &br->bufs[head]; | ^~~~~~~~~~~~~~~ In file included from include/linux/io_uring.h:7, from io_uring/kbuf.c:10: include/uapi/linux/io_uring.h: In function 'io_buffer_select': include/uapi/linux/io_uring.h:628:41: note: while referencing 'bufs' 628 | struct io_uring_buf bufs[0]; | ^~~~ [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers") Cc: Jens Axboe Cc: Pavel Begunkov Cc: "Gustavo A. R. Silva" Cc: stable@vger.kernel.org Cc: io-uring@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20230105190507.gonna.131-kees@kernel.org Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/io_uring.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -625,7 +625,7 @@ struct io_uring_buf_ring { __u16 resv3; __u16 tail; }; - struct io_uring_buf bufs[0]; + __DECLARE_FLEX_ARRAY(struct io_uring_buf, bufs); }; };