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 CCE61C433EF for ; Mon, 7 Mar 2022 10:11:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239199AbiCGKHo (ORCPT ); Mon, 7 Mar 2022 05:07:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239309AbiCGJta (ORCPT ); Mon, 7 Mar 2022 04:49:30 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC83F2C11D; Mon, 7 Mar 2022 01:42:58 -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 dfw.source.kernel.org (Postfix) with ESMTPS id D773160C7D; Mon, 7 Mar 2022 09:42:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDCF5C340E9; Mon, 7 Mar 2022 09:42:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646646168; bh=CwRWz1iT0e8U+3QDeSULEs/jxlFAROz4A7uwq2PHYqA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bWfALnZ0rhIik1kIBpAQ0ZCMpol63qZ+Pe37e/YRl3RAJV5kDRRxkGAnnDp1Ya+T5 TiuBln/ksIbyqi0rH7vjGI/96J1gAXD3Cg2srpTpPlkUWS9fWOcl68PZOGiakuny8T KxTddlXacK4HEBB5gA0Vk7sKnHPvX+xcSAiJ1Fu8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Eric Dumazet , John Fastabend , Jakub Sitnicki , Daniel Borkmann , Jakub Kicinski Subject: [PATCH 5.15 155/262] bpf, sockmap: Do not ignore orig_len parameter Date: Mon, 7 Mar 2022 10:18:19 +0100 Message-Id: <20220307091706.810903558@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220307091702.378509770@linuxfoundation.org> References: <20220307091702.378509770@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet commit 60ce37b03917e593d8e5d8bcc7ec820773daf81d upstream. Currently, sk_psock_verdict_recv() returns skb->len This is problematic because tcp_read_sock() might have passed orig_len < skb->len, due to the presence of TCP urgent data. This causes an infinite loop from tcp_read_sock() Followup patch will make tcp_read_sock() more robust vs bad actors. Fixes: ef5659280eb1 ("bpf, sockmap: Allow skipping sk_skb parser program") Reported-by: syzbot Signed-off-by: Eric Dumazet Acked-by: John Fastabend Acked-by: Jakub Sitnicki Tested-by: Jakub Sitnicki Acked-by: Daniel Borkmann Link: https://lore.kernel.org/r/20220302161723.3910001-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/core/skmsg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -1153,7 +1153,7 @@ static int sk_psock_verdict_recv(read_de struct sk_psock *psock; struct bpf_prog *prog; int ret = __SK_DROP; - int len = skb->len; + int len = orig_len; /* clone here so sk_eat_skb() in tcp_read_sock does not drop our data */ skb = skb_clone(skb, GFP_ATOMIC);