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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 88ABBC433DF for ; Thu, 18 Jun 2020 02:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 683F2214DB for ; Thu, 18 Jun 2020 02:29:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592447399; bh=kE4r/DncWHkvPGYKD8JFmPlP3Dy3jow243D+vlxfFl4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zN5MSZ18g3WrEcQogV+Ql7CRO2mw8Zmlljn9LH96D2xXwYh7uVmJUSIlvoUs6dGRr 2FJ7qs+BHsTYFZthmYTxNEDjVNVie99JU+Zb0EjYHeGKsR4ij6XB8Xxwb9PmxJLfTK +tYYdlm2eyCeHCEx7RCzdAs8lpt/JI74KN/kGXDE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387691AbgFRC36 (ORCPT ); Wed, 17 Jun 2020 22:29:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:46358 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729283AbgFRBQB (ORCPT ); Wed, 17 Jun 2020 21:16:01 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 112C12088E; Thu, 18 Jun 2020 01:15:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592442961; bh=kE4r/DncWHkvPGYKD8JFmPlP3Dy3jow243D+vlxfFl4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nTTbtMmVfHW6AZE1kOfTycl3cXcd/upOqFbR+5RpAkqnCw7xzI47h5gh9on4Rk9Dd PiPpzNY1BSDlt/Xma4KFUJQZOHOc8H37fb7NK5/t64N4zlWgSMmgC29tZr2x1GRcAA M8fGBACy8jSGmS6V1U+OduEKHLEIqQcbkjB5OBhg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: dihu , Alexei Starovoitov , John Fastabend , Jakub Sitnicki , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.7 367/388] bpf/sockmap: Fix kernel panic at __tcp_bpf_recvmsg Date: Wed, 17 Jun 2020 21:07:44 -0400 Message-Id: <20200618010805.600873-367-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618010805.600873-1-sashal@kernel.org> References: <20200618010805.600873-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 9c5540887fbe..7aa68f4aae6c 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -64,6 +64,9 @@ 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; } -- 2.25.1