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,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 2E5C3C33CB3 for ; Thu, 16 Jan 2020 16:54:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05A1022522 for ; Thu, 16 Jan 2020 16:54:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579193646; bh=64x82PQuv5pebgDgHhtSr+hFf0pKyR4SaaHfSStuJYU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yS33VNtVOe+OW5Rs/iCO8O8B7He1HHg2PGv1evHVRPzkx4q5uQySGqK0EKkKXrsNX 7BZl7Ly9bjT1rGyIbnDR5l4WryWMJfSgD3gE0Zdl+OpRhO29ZAWHV5uXxqAnLzeCAh OpvlyhrRmM/qPjo5C8eiQGY0SSm/pfxWenUr2TIk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731489AbgAPQyE (ORCPT ); Thu, 16 Jan 2020 11:54:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:37938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731221AbgAPQxv (ORCPT ); Thu, 16 Jan 2020 11:53:51 -0500 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 DB9912464B; Thu, 16 Jan 2020 16:53:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579193630; bh=64x82PQuv5pebgDgHhtSr+hFf0pKyR4SaaHfSStuJYU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Piat3vyyqytUa/5WiJyI56c9wyzuGNQd5XuC9KHUahU7brCcjE6jtcoAr8r0Gte8D Ysb0g/gPC5++4a+oY76TFmVPaKnL00V9bk5Fyk+CHAECwUcYJ3RjK7ToQRlbqJCdJ/ 2BQ4dlqr+T5ybTNMQSYa40hTrbIgWZhoiT/LHKbo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: John Fastabend , Dan Carpenter , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 164/205] bpf: skmsg, fix potential psock NULL pointer dereference Date: Thu, 16 Jan 2020 11:42:19 -0500 Message-Id: <20200116164300.6705-164-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116164300.6705-1-sashal@kernel.org> References: <20200116164300.6705-1-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: John Fastabend [ Upstream commit 8163999db445021f2651a8a47b5632483e8722ea ] Report from Dan Carpenter, net/core/skmsg.c:792 sk_psock_write_space() error: we previously assumed 'psock' could be null (see line 790) net/core/skmsg.c 789 psock = sk_psock(sk); 790 if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))) Check for NULL 791 schedule_work(&psock->work); 792 write_space = psock->saved_write_space; ^^^^^^^^^^^^^^^^^^^^^^^^ 793 rcu_read_unlock(); 794 write_space(sk); Ensure psock dereference on line 792 only occurs if psock is not null. Reported-by: Dan Carpenter Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/skmsg.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 0675d022584e..ded2d5227678 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -793,15 +793,18 @@ static void sk_psock_strp_data_ready(struct sock *sk) static void sk_psock_write_space(struct sock *sk) { struct sk_psock *psock; - void (*write_space)(struct sock *sk); + void (*write_space)(struct sock *sk) = NULL; rcu_read_lock(); psock = sk_psock(sk); - if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))) - schedule_work(&psock->work); - write_space = psock->saved_write_space; + if (likely(psock)) { + if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) + schedule_work(&psock->work); + write_space = psock->saved_write_space; + } rcu_read_unlock(); - write_space(sk); + if (write_space) + write_space(sk); } int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock) -- 2.20.1