Received: by 2002:a25:d7c1:0:0:0:0:0 with SMTP id o184csp2253168ybg; Sun, 27 Oct 2019 14:27:26 -0700 (PDT) X-Google-Smtp-Source: APXvYqyAJakKlqWyM2zTq7GAnJXs/uQfCkd0q+dc7JjkNyI6iA9n899xcC/+GCTMhGSdvECUPPUL X-Received: by 2002:a50:9269:: with SMTP id j38mr16007669eda.5.1572211645922; Sun, 27 Oct 2019 14:27:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1572211645; cv=none; d=google.com; s=arc-20160816; b=cQ0OJzLL77yy5k2Ipiwtc88kOyei86ep8g/nh4Hs8cm8Ig3n7D97BnC8NPNqPbvduG YMkYE2VcYBGNrjQceFe8nA1JDoBaktjSO3pLIhfJoKhefwcnLLf+f0cIWq1msOIE5zly gY2j+VnPOnJ5XIWv0G30e9AXOu0bOwkHnU5Dsd7/ER1zOLLvCxAt6UgxSD0zQsAjGJ63 wcb5TJa631spIofI32baAqI9PWVxqdyYzyiFgwE1FVJVF7gSe9ZpksJAhaVRLVhX6x+f +jtto+hqJKdejGMAY960HSNVinsK7jToosI89Xltnv0VpAGdPkBp7TjHkmZkemQ3GVmD UcUg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=JvtDbmWb9MrrJ3pa3XvDPOWxlyXKDzBwoYX06puI4cQ=; b=snQcRaHJxHtING3VKcENQR3Onnh9cr9YNoDg5U8ptNho5q7IH+sgT55kCgjOiO3oHv e6MXyiNLjyoDsVvgts7ftxjOcO42BavNmL3L551oPPoclNoH6ypFJuixlyq/dcQkpqru g8+6H4Itsrfb8p3OtBaGn9b3tz9OYUAYKy484iYFoCj0TihmW31lKcnnPEYZ10MIr9br FkrbvuFrsLumGzMVv10AQEpTwISiAls0mQqFXYUbw+gRGeV8Kst/Wr4irVvpno9V7Q2M 2RfvK2o/cJF6AVUHkw23vlJRVD4gaOProXZ3qS6sln1UNI9nnOUA3DPt9e8c52Bw0qSp cevw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=NGkeeb7Y; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f12si971706ejc.98.2019.10.27.14.27.02; Sun, 27 Oct 2019 14:27:25 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=NGkeeb7Y; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732758AbfJ0VZb (ORCPT + 99 others); Sun, 27 Oct 2019 17:25:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:47400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732745AbfJ0VZ3 (ORCPT ); Sun, 27 Oct 2019 17:25:29 -0400 Received: from localhost (100.50.158.77.rev.sfr.net [77.158.50.100]) (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 8018A21850; Sun, 27 Oct 2019 21:25:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572211529; bh=ti2/6AttwyI/CUbzp9Nn0c4NFrp3fhY5UsaMZgfOQDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NGkeeb7Yekds7MLDLBtykcbVKQBgxN1ETDC52EwQaTFeZCHTsBSG6AlqJVbudeNvI tVW9UgQT7M2CdLoVaF7AFDExjK4JkivUXK3U2UnfnQm8sLtdRMjJbD4/qSWXfKwjbe r4kkvGP8THx41++6jjSlD+4jJtwiV6P2cP4mtWlE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Begunkov , Jens Axboe , Sasha Levin Subject: [PATCH 5.3 139/197] io_uring: Fix race for sqes with userspace Date: Sun, 27 Oct 2019 22:00:57 +0100 Message-Id: <20191027203359.214148601@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191027203351.684916567@linuxfoundation.org> References: <20191027203351.684916567@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: Pavel Begunkov [ Upstream commit 935d1e45908afb8853c497f2c2bbbb685dec51dc ] io_ring_submit() finalises with 1. io_commit_sqring(), which releases sqes to the userspace 2. Then calls to io_queue_link_head(), accessing released head's sqe Reorder them. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/io_uring.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 518042cc6628b..d447f43d64a24 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2488,13 +2488,14 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) submit++; io_submit_sqe(ctx, &s, statep, &link); } - io_commit_sqring(ctx); if (link) io_queue_sqe(ctx, link, &link->submit); if (statep) io_submit_state_end(statep); + io_commit_sqring(ctx); + return submit; } -- 2.20.1