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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D024C433FE for ; Wed, 9 Mar 2022 16:25:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235798AbiCIQ0F (ORCPT ); Wed, 9 Mar 2022 11:26:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238146AbiCIQV3 (ORCPT ); Wed, 9 Mar 2022 11:21:29 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A993115339B; Wed, 9 Mar 2022 08:19:32 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 502CBB82206; Wed, 9 Mar 2022 16:19:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC727C340F3; Wed, 9 Mar 2022 16:19:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646842770; bh=qz2/+MsYFE+k4rvs9wvf9F2qqKY54LYjp3wUAUnPR30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LaDaAh2rF7Wm/tsatS9H1qaRIwCgoTeNvq5hKkH7uJ8QV+hGGpr/opudxQBJLmjh/ 6T9e+BuX90dRYrIcwEzFtqIe9+8qqGNw+9qCfs8XPTgjK3gd1/A+CJazktzG+ndpxQ lNQC94xqWLs81GUJ+9+SqMFiIp5zc95ul+s8fMT/NPAj6q9T5563e0G0ILv+PMlpTH zFVwjQPvCYXfyLLQmlj+wTfJLfeLaF+Uhit+QA8/svbAHuuZlJTxk1FA/ubGsQ7Fbb Y/VdtBGX7+VUzseME/uquKyKOVi48ivCN9wNqFW9bmooy26Jn/nfenSOh3JNciYMVj k5TQLZkrZVsvA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , John Fastabend , Jakub Sitnicki , Daniel Borkmann , Jakub Kicinski , Sasha Levin , davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.16 24/27] tcp: make tcp_read_sock() more robust Date: Wed, 9 Mar 2022 11:17:01 -0500 Message-Id: <20220309161711.135679-24-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220309161711.135679-1-sashal@kernel.org> References: <20220309161711.135679-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet [ Upstream commit e3d5ea2c011ecb16fb94c56a659364e6b30fac94 ] If recv_actor() returns an incorrect value, tcp_read_sock() might loop forever. Instead, issue a one time warning and make sure to make progress. Signed-off-by: Eric Dumazet Acked-by: John Fastabend Acked-by: Jakub Sitnicki Acked-by: Daniel Borkmann Link: https://lore.kernel.org/r/20220302161723.3910001-2-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 28abb0bb1c51..38f936785179 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1653,11 +1653,13 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, if (!copied) copied = used; break; - } else if (used <= len) { - seq += used; - copied += used; - offset += used; } + if (WARN_ON_ONCE(used > len)) + used = len; + seq += used; + copied += used; + offset += used; + /* If recv_actor drops the lock (e.g. TCP splice * receive) the skb pointer might be invalid when * getting here: tcp_collapse might have deleted it -- 2.34.1