From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 223B61863 for ; Wed, 28 Dec 2022 15:02:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98155C433D2; Wed, 28 Dec 2022 15:02:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672239733; bh=t+DdR3AGDJohcKG6a+DJBy8uLuku062ruhfRulGYuM8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l8o84xgpVKWhTZnEZDcb+rNhJL3wKfupHkCc1fhffsghxnZFPOKr3Sog2aUKSzNJj 700GswYBmjGu+P/h5IU60ola3zmJsQjpxxq+/G/UkgBFGgrjqcuWSvL4qf8Qn2DWgu /XRlQ0FZ6/6PcygC5MLBJEYQ78x3BBTRxWRLgVBA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pengcheng Yang , Daniel Borkmann , Jakub Sitnicki , Sasha Levin Subject: [PATCH 5.15 263/731] bpf, sockmap: Fix data loss caused by using apply_bytes on ingress redirect Date: Wed, 28 Dec 2022 15:36:10 +0100 Message-Id: <20221228144304.186660751@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144256.536395940@linuxfoundation.org> References: <20221228144256.536395940@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Pengcheng Yang [ Upstream commit 9072931f020bfd907d6d89ee21ff1481cd78b407 ] 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 Signed-off-by: Daniel Borkmann Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/1669718441-2654-4-git-send-email-yangpc@wangsu.com Signed-off-by: Sasha Levin --- 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 2db868ca32af..b4b642e3de78 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); -- 2.35.1