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 DBF7AC433EF for ; Wed, 9 Mar 2022 16:45:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236159AbiCIQqs (ORCPT ); Wed, 9 Mar 2022 11:46:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239006AbiCIQcD (ORCPT ); Wed, 9 Mar 2022 11:32:03 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C91531A7DB9; Wed, 9 Mar 2022 08:26:58 -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 471A5B82256; Wed, 9 Mar 2022 16:26:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99638C340F8; Wed, 9 Mar 2022 16:26:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646843166; bh=xAX3loMR5mPRaq31kqGAqN9kE+3WU6JXu+F/CbN4ztE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cHezaA7+FaZ9/9/JXE10AaJn5SGnujYa8r0TBiSTSMjpVLd6FgGqj+/+mTdoXKczg 5qxUi4Y/9WamrgAsIJCxwjn9MbCHjvButGknWXctWuNT3STd69kXjngl+pUnJ3pnMw 90nvJghycuNHngy0hcUb7gq33WTgL/oFErWwbM8RLaIeZgc4Q3HLtk51TX1Am1BMus 2uoAGVRtnPhQQQQnTqSAsqOEx8Nrcdl3J2yZc7zNQ4v/rPEfV18j0wT+Vgd25yB2pl SALShdJLLG+BW3Izwk7A5dJ2+Xz0vNK0FoABhc4biUkWiNC60E3jU5VygwkoV/fsae hojgA+83J9IIQ== 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 4.19 11/14] tcp: make tcp_read_sock() more robust Date: Wed, 9 Mar 2022 11:25:04 -0500 Message-Id: <20220309162508.137035-11-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220309162508.137035-1-sashal@kernel.org> References: <20220309162508.137035-1-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 4dce1b418acc..f7795488b0ad 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1669,11 +1669,13 @@ 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