From patchwork Tue Jun 23 19:57:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 223458 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED7B9C433E0 for ; Tue, 23 Jun 2020 20:31:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C524D20723 for ; Tue, 23 Jun 2020 20:31:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592944292; bh=VtCfLABy9jFIpwB0CiuNGNBuZRK0+oBQP1HeBXvQ2ps=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=E+lqz/xun1OzkfsxBKQLYllQryxiVXk8iIGEXCPxD4lMzYdTcSqD/He6m2FSs4uSx 09lcHF5yaL6G1OujQgOUXH99tLl64P5+eDvmcl/rn12J4HSefc/8iCB71FNXHiXBB5 8AP6FXhVQqzGzZKXg8yZBaUUnOD+e7sr3IZMM6dE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390490AbgFWUba (ORCPT ); Tue, 23 Jun 2020 16:31:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:52078 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391204AbgFWUb3 (ORCPT ); Tue, 23 Jun 2020 16:31:29 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 358EF2070E; Tue, 23 Jun 2020 20:31:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592944289; bh=VtCfLABy9jFIpwB0CiuNGNBuZRK0+oBQP1HeBXvQ2ps=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yvYaoQyBy/S8txccoQ0a9n7aOTZodDfqeRVUFtXS5mYcPpRZz5dEqW5RtkffI2pe5 05hwTca/3gNy45ZVvTmLDtxRENp4QIMU2DjGt27+aplibW7jUwPH0Yh5o0aKt7c8Vc 9Z4ucA2jTez13UEpqKdynNwTaxZxfYfj2NGaVI+Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, dihu , Alexei Starovoitov , John Fastabend , Jakub Sitnicki , Sasha Levin Subject: [PATCH 5.4 247/314] bpf/sockmap: Fix kernel panic at __tcp_bpf_recvmsg Date: Tue, 23 Jun 2020 21:57:22 +0200 Message-Id: <20200623195350.731188809@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195338.770401005@linuxfoundation.org> References: <20200623195338.770401005@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: dihu [ Upstream commit 487082fb7bd2a32b66927d2b22e3a81b072b44f0 ] When user application calls read() with MSG_PEEK flag to read data of bpf sockmap socket, kernel panic happens at __tcp_bpf_recvmsg+0x12c/0x350. sk_msg is not removed from ingress_msg queue after read out under MSG_PEEK flag is set. Because it's not judged whether sk_msg is the last msg of ingress_msg queue, the next sk_msg may be the head of ingress_msg queue, whose memory address of sg page is invalid. So it's necessary to add check codes to prevent this problem. [20759.125457] BUG: kernel NULL pointer dereference, address: 0000000000000008 [20759.132118] CPU: 53 PID: 51378 Comm: envoy Tainted: G E 5.4.32 #1 [20759.140890] Hardware name: Inspur SA5212M4/YZMB-00370-109, BIOS 4.1.12 06/18/2017 [20759.149734] RIP: 0010:copy_page_to_iter+0xad/0x300 [20759.270877] __tcp_bpf_recvmsg+0x12c/0x350 [20759.276099] tcp_bpf_recvmsg+0x113/0x370 [20759.281137] inet_recvmsg+0x55/0xc0 [20759.285734] __sys_recvfrom+0xc8/0x130 [20759.290566] ? __audit_syscall_entry+0x103/0x130 [20759.296227] ? syscall_trace_enter+0x1d2/0x2d0 [20759.301700] ? __audit_syscall_exit+0x1e4/0x290 [20759.307235] __x64_sys_recvfrom+0x24/0x30 [20759.312226] do_syscall_64+0x55/0x1b0 [20759.316852] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: dihu Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20200605084625.9783-1-anny.hu@linux.alibaba.com Signed-off-by: Sasha Levin --- net/ipv4/tcp_bpf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 69b0254083904..ad9f382027311 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -96,6 +96,9 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock, } while (i != msg_rx->sg.end); if (unlikely(peek)) { + if (msg_rx == list_last_entry(&psock->ingress_msg, + struct sk_msg, list)) + break; msg_rx = list_next_entry(msg_rx, list); continue; }