From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4C59C433FF for ; Mon, 29 Jul 2019 19:56:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9945C21655 for ; Mon, 29 Jul 2019 19:56:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564430172; bh=O3KG9Nz1k06UKZGcnzV3zAkp4uWNexemALwHWlzerqQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uIJCBJbZiN1A0kRkbIPpP9P/sD9zekLyTeIDUJRGxcnqMAhGm2sydzJJXOX2nPafN DYVYenmXO21G21Nznytt3KDvmwdist/KsczIPzetKABqSJYKjdNAK9fbBFyz4v3Wfd sK6igw+BzxN+aN6TUeYSixNMj00gs7Y1xmgI0HmE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404327AbfG2T4K (ORCPT ); Mon, 29 Jul 2019 15:56:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:49006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404315AbfG2T4H (ORCPT ); Mon, 29 Jul 2019 15:56:07 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F27F321655; Mon, 29 Jul 2019 19:56:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564430166; bh=O3KG9Nz1k06UKZGcnzV3zAkp4uWNexemALwHWlzerqQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MPK2Rn1JzBsf9EJUm8zKXmkEgqPOhRMCOaZeBhrW5V9Vz3p9OvZSuUm166A6n39vP VO1QMrOW0sni4ELjQFK29wUkX0Dheb99nLPvwDOvBYQ3ei7l1ptW54f32wADfTT5QO NKrIqX8UdlvNjsNzSyMrovBF5rxIke248Gn8abE0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhengyuan Liu , Jens Axboe Subject: [PATCH 5.2 201/215] io_uring: fix the sequence comparison in io_sequence_defer Date: Mon, 29 Jul 2019 21:23:17 +0200 Message-Id: <20190729190814.779830632@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190739.971253303@linuxfoundation.org> References: <20190729190739.971253303@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhengyuan Liu commit dbd0f6d6c2a11eb9c31ca9cd454f95bb5713e92e upstream. sq->cached_sq_head and cq->cached_cq_tail are both unsigned int. If cached_sq_head overflows before cached_cq_tail, then we may miss a barrier req. As cached_cq_tail always follows cached_sq_head, the NQ should be enough. Cc: stable@vger.kernel.org Fixes: de0617e46717 ("io_uring: add support for marking commands as draining") Signed-off-by: Zhengyuan Liu Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -425,7 +425,7 @@ static inline bool io_sequence_defer(str if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN) return false; - return req->sequence > ctx->cached_cq_tail + ctx->sq_ring->dropped; + return req->sequence != ctx->cached_cq_tail + ctx->sq_ring->dropped; } static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)