From patchwork Fri Jan 22 14:12:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 369395 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 893D9C433DB for ; Fri, 22 Jan 2021 14:55:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EEA3239EE for ; Fri, 22 Jan 2021 14:55:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728745AbhAVOyp (ORCPT ); Fri, 22 Jan 2021 09:54:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:40744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728647AbhAVOYP (ORCPT ); Fri, 22 Jan 2021 09:24:15 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E314523B05; Fri, 22 Jan 2021 14:18:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611325094; bh=Y3NRp2Z/dQded9CsO0lQwzg1I75lXwOF3wumneecBZ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CIPlUH2VAWv4IGCTVq8+T2KuaHnM44qFqCXeq7ay5RWjY6OMnEowxAONKM3lBHkUP 11AjyF8BtUV5DwUgXIWnRxldUfiAmU24xEW7Y6YR3ucrCoJ0K/YXQQYgThSOTwI7M3 Mg14vQmQxukrT1e+KInN0EvA/65qTGOsOPMpUkU0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Baptiste Lepers , Willem de Bruijn , Jakub Kicinski Subject: [PATCH 5.10 13/43] udp: Prevent reuseport_select_sock from reading uninitialized socks Date: Fri, 22 Jan 2021 15:12:29 +0100 Message-Id: <20210122135736.181768364@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122135735.652681690@linuxfoundation.org> References: <20210122135735.652681690@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Baptiste Lepers [ Upstream commit fd2ddef043592e7de80af53f47fa46fd3573086e ] reuse->socks[] is modified concurrently by reuseport_add_sock. To prevent reading values that have not been fully initialized, only read the array up until the last known safe index instead of incorrectly re-reading the last index of the array. Fixes: acdcecc61285f ("udp: correct reuseport selection with connected sockets") Signed-off-by: Baptiste Lepers Acked-by: Willem de Bruijn Link: https://lore.kernel.org/r/20210107051110.12247-1-baptiste.lepers@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/core/sock_reuseport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -293,7 +293,7 @@ select_by_hash: i = j = reciprocal_scale(hash, socks); while (reuse->socks[i]->sk_state == TCP_ESTABLISHED) { i++; - if (i >= reuse->num_socks) + if (i >= socks) i = 0; if (i == j) goto out;