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 E8936C433EF for ; Wed, 9 Mar 2022 16:32:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239612AbiCIQdJ (ORCPT ); Wed, 9 Mar 2022 11:33:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235556AbiCIQXh (ORCPT ); Wed, 9 Mar 2022 11:23:37 -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 03B41522C8; Wed, 9 Mar 2022 08:21:48 -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 9E0C5B82222; Wed, 9 Mar 2022 16:21:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8ECE4C340E8; Wed, 9 Mar 2022 16:21:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646842905; bh=lZ6F42Gdq8qQqyDaBwpPUjTLw8aAQQXBNbxuiWWX614=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hk7J+VqZ1rJXUGgmcJ/iehCR8TN2jk2ydE6ctqYoBoK85DqE6xrEKYcCe6VdKI0CA x90khemOvPAjwA5QUhSYLbvrLhsB9PENNLuVqP03bFgYb0GPpdNHyvCo28DetOyMqR 0Iv9gnfEXEGIkGUEBdFwJ5eVfS2irAy3l7pwktCQVdodjwK36ohh0sJiWyueLxL3Ys jTFepmj0yM81UZQdPomSDRP+sA6ikFeu98rcoDOKs3r178Oqf8z4SiUkMiX2Bhiw8H XsVkbAiEQ/dHJ4/V3tMjQy2yHB0nHqXU1Lwt/GmR/VBifN7lBMsKDONL3p7pEno47x XjH7AfsGMDRww== 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 5.15 21/24] tcp: make tcp_read_sock() more robust Date: Wed, 9 Mar 2022 11:19:40 -0500 Message-Id: <20220309161946.136122-21-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220309161946.136122-1-sashal@kernel.org> References: <20220309161946.136122-1-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: linux-kernel@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 f48f1059b31a..ef68d55e0944 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1663,11 +1663,13 @@ 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