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 A76D4C4332F for ; Tue, 22 Nov 2022 02:06:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232464AbiKVCGA (ORCPT ); Mon, 21 Nov 2022 21:06:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232495AbiKVCFd (ORCPT ); Mon, 21 Nov 2022 21:05:33 -0500 X-Greylist: delayed 378 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 21 Nov 2022 18:05:22 PST Received: from zg8tmja2lje4os4yms4ymjma.icoremail.net (zg8tmja2lje4os4yms4ymjma.icoremail.net [206.189.21.223]) by lindbergh.monkeyblade.net (Postfix) with SMTP id D751FE2B5F for ; Mon, 21 Nov 2022 18:05:22 -0800 (PST) Received: from 102.wangsu.com (unknown [59.61.78.232]) by app2 (Coremail) with SMTP id SyJltADnLkvOLHxjiGsAAA--.531S5; Tue, 22 Nov 2022 09:58:56 +0800 (CST) From: Pengcheng Yang To: bpf@vger.kernel.org, netdev@vger.kernel.org, John Fastabend , Daniel Borkmann , Jakub Sitnicki , Lorenz Bauer Cc: Pengcheng Yang Subject: [PATCH RESEND bpf 3/4] bpf, sockmap: Fix data loss caused by using apply_bytes on ingress redirect Date: Tue, 22 Nov 2022 09:58:28 +0800 Message-Id: <1669082309-2546-4-git-send-email-yangpc@wangsu.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1669082309-2546-1-git-send-email-yangpc@wangsu.com> References: <1669082309-2546-1-git-send-email-yangpc@wangsu.com> X-CM-TRANSID: SyJltADnLkvOLHxjiGsAAA--.531S5 X-Coremail-Antispam: 1UD129KBjvdXoWrKr4ftw4rGrW8Xr45CryDZFb_yoWfWwbE9r W0yF9xGry8WF1IkF4Du3y5tF92grs2vFn3Kr1xJFW7t348AFyUArs5XFn3ZFWkWFW2yFyq g34kXr4UZa4aqjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJ3UbIYCTnIWIevJa73UjIFyTuYvj4RJUUUUUUUU X-CM-SenderInfo: p1dqw1nf6zt0xjvxhudrp/ Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Use apply_bytes on ingress redirect, when apply_bytes is less than the length of msg data, some data may be skipped and lost in bpf_tcp_ingress(). If there is still data in the scatterlist that has not been consumed, we cannot move the msg iter. Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Pengcheng Yang --- net/ipv4/tcp_bpf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 1390d72..3cc0346 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -45,8 +45,11 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock, tmp->sg.end = i; if (apply) { apply_bytes -= size; - if (!apply_bytes) + if (!apply_bytes) { + if (sge->length) + sk_msg_iter_var_prev(i); break; + } } } while (i != msg->sg.end); -- 1.8.3.1