From patchwork Mon Jun 13 10:11:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Yudaken X-Patchwork-Id: 12879278 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 37854CCA47B for ; Mon, 13 Jun 2022 10:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229926AbiFMKMR (ORCPT ); Mon, 13 Jun 2022 06:12:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230509AbiFMKMP (ORCPT ); Mon, 13 Jun 2022 06:12:15 -0400 Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E462118 for ; Mon, 13 Jun 2022 03:12:13 -0700 (PDT) Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 25CMw8Pu015303 for ; Mon, 13 Jun 2022 03:12:12 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=FEJ9cV9D2JqkfKjBRINWLlNmpSiGIlxGX0X5mdkJGvM=; b=jvtWBzKS4KNB0N/SAAask6NogC3tT09v+bLqmfaz8DhRXDala4mfpK0/x9D73w6AeeeL Dyb6itZSpvnX0U6wk29DJByXl6IDLjHFn9hhvZNXjzjjECNcFBZczuL7kLEBnMNl9z1U S2zoKNany7kowepq2jJ/TM1p5JJteFAAPFA= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3gmrvuyckb-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 13 Jun 2022 03:12:12 -0700 Received: from twshared25107.07.ash9.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Mon, 13 Jun 2022 03:12:11 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id 1C4D21992ADF; Mon, 13 Jun 2022 03:12:04 -0700 (PDT) From: Dylan Yudaken To: , , CC: , Dylan Yudaken Subject: [PATCH 1/3] io_uring: fix index calculation Date: Mon, 13 Jun 2022 03:11:55 -0700 Message-ID: <20220613101157.3687-2-dylany@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220613101157.3687-1-dylany@fb.com> References: <20220613101157.3687-1-dylany@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: oxXYp8-UK769HmjVXmbZ9q0VhWGscUuL X-Proofpoint-GUID: oxXYp8-UK769HmjVXmbZ9q0VhWGscUuL X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.517,FMLib:17.11.64.514 definitions=2022-06-13_03,2022-06-13_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org When indexing into a provided buffer ring, do not subtract 1 from the index. Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers") Signed-off-by: Dylan Yudaken --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 3aab4182fd89..9cf9aff51b70 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3888,7 +3888,7 @@ static void __user *io_ring_buffer_select(struct io_kiocb *req, size_t *len, buf = &br->bufs[head]; } else { int off = head & (IO_BUFFER_LIST_BUF_PER_PAGE - 1); - int index = head / IO_BUFFER_LIST_BUF_PER_PAGE - 1; + int index = head / IO_BUFFER_LIST_BUF_PER_PAGE; buf = page_address(bl->buf_pages[index]); buf += off; }