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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 3C8B5C43381 for ; Mon, 1 Apr 2019 17:12:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C2CE21925 for ; Mon, 1 Apr 2019 17:12:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554138764; bh=ZPyXtIaO+nAxHno+XC1zP+hCrakaVr0T3uFhSnat54s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wujm1YvvSidHDUrlqTzjqXNSu5VEcd1bde/r1rw3ERfRYuLER9Mga3TDmVBhwUFBJ ywWy62nd79qwFJwu450D59D//LOisXi1Li+f99X8hvermgUZQQGPlDu0YBUdWgiYkJ gqoyEG3ZvJAwmlVGaroS0V5WVkM1jrh3PX09ISXk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730394AbfDARMm (ORCPT ); Mon, 1 Apr 2019 13:12:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:34152 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729731AbfDARMb (ORCPT ); Mon, 1 Apr 2019 13:12:31 -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 BBED621929; Mon, 1 Apr 2019 17:12:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554138751; bh=ZPyXtIaO+nAxHno+XC1zP+hCrakaVr0T3uFhSnat54s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q0aSTvv4T/7UOsMqZpHTqPn02YyrEHVpdHEa3Ra/ebqk5eTA1300qjIL0FkG8SEuQ fVLLAm8q1vWVHt4owNltYDiHpMCcpZcvh8fyB9mwbx/eyZF/f+dQNP5EqrXWja7R+V UqIvN9Og/5+RaiQ4I/vWHmfMwd37Onv/ZcK8lJYQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Abeni , "David S. Miller" , Christoph Paasch Subject: [PATCH 4.19 011/134] net: datagram: fix unbounded loop in __skb_try_recv_datagram() Date: Mon, 1 Apr 2019 19:00:47 +0200 Message-Id: <20190401170045.348959518@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170044.243719205@linuxfoundation.org> References: <20190401170044.243719205@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit 0b91bce1ebfc797ff3de60c8f4a1e6219a8a3187 ] Christoph reported a stall while peeking datagram with an offset when busy polling is enabled. __skb_try_recv_datagram() uses as the loop termination condition 'queue empty'. When peeking, the socket queue can be not empty, even when no additional packets are received. Address the issue explicitly checking for receive queue changes, as currently done by __skb_wait_for_more_packets(). Fixes: 2b5cd0dfa384 ("net: Change return type of sk_busy_loop from bool to void") Reported-and-tested-by: Christoph Paasch Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/datagram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -279,7 +279,7 @@ struct sk_buff *__skb_try_recv_datagram( break; sk_busy_loop(sk, flags & MSG_DONTWAIT); - } while (!skb_queue_empty(&sk->sk_receive_queue)); + } while (sk->sk_receive_queue.prev != *last); error = -EAGAIN;