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 90483C7EE25 for ; Wed, 7 Jun 2023 20:59:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235617AbjFGU67 (ORCPT ); Wed, 7 Jun 2023 16:58:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235704AbjFGU64 (ORCPT ); Wed, 7 Jun 2023 16:58:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5536F1FE3 for ; Wed, 7 Jun 2023 13:58:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3540F648A2 for ; Wed, 7 Jun 2023 20:58:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45EE9C433EF; Wed, 7 Jun 2023 20:58:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1686171513; bh=da/VMOT6pjZCU031IC5tNYnfdbV3xSFtVNUuAEcG9o0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PhLePQXPlm9EXj9PO7osIVOWeyqDTmKTrl8d8SkbiTaLJF22cm0uPq2zqT8J2YWW7 Cib7y9mKjH8Dts05Sv4c2bTZrCk5IOc0RsrpVcgzCk6/L0nKIvNZ5T0E64Uv63ulXJ JjVYZv/TVEkazBKhYud1P0LyN25QfkhvcU3ICEn0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzkaller , Kuniyuki Iwashima , Willem de Bruijn , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 017/159] af_packet: Fix data-races of pkt_sk(sk)->num. Date: Wed, 7 Jun 2023 22:15:20 +0200 Message-ID: <20230607200904.237272002@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230607200903.652580797@linuxfoundation.org> References: <20230607200903.652580797@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 822b5a1c17df7e338b9f05d1cfe5764e37c7f74f ] syzkaller found a data race of pkt_sk(sk)->num. The value is changed under lock_sock() and po->bind_lock, so we need READ_ONCE() to access pkt_sk(sk)->num without these locks in packet_bind_spkt(), packet_bind(), and sk_diag_fill(). Note that WRITE_ONCE() is already added by commit c7d2ef5dd4b0 ("net/packet: annotate accesses to po->bind"). BUG: KCSAN: data-race in packet_bind / packet_do_bind write (marked) to 0xffff88802ffd1cee of 2 bytes by task 7322 on cpu 0: packet_do_bind+0x446/0x640 net/packet/af_packet.c:3236 packet_bind+0x99/0xe0 net/packet/af_packet.c:3321 __sys_bind+0x19b/0x1e0 net/socket.c:1803 __do_sys_bind net/socket.c:1814 [inline] __se_sys_bind net/socket.c:1812 [inline] __x64_sys_bind+0x40/0x50 net/socket.c:1812 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff88802ffd1cee of 2 bytes by task 7318 on cpu 1: packet_bind+0xbf/0xe0 net/packet/af_packet.c:3322 __sys_bind+0x19b/0x1e0 net/socket.c:1803 __do_sys_bind net/socket.c:1814 [inline] __se_sys_bind net/socket.c:1812 [inline] __x64_sys_bind+0x40/0x50 net/socket.c:1812 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x0300 -> 0x0000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7318 Comm: syz-executor.4 Not tainted 6.3.0-13380-g7fddb5b5300c #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 96ec6327144e ("packet: Diag core and basic socket info dumping") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzkaller Signed-off-by: Kuniyuki Iwashima Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/r/20230524232934.50950-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 4 ++-- net/packet/diag.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ce484305be881..05a0b1d8c3721 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3259,7 +3259,7 @@ static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data)); name[sizeof(uaddr->sa_data)] = 0; - return packet_do_bind(sk, name, 0, pkt_sk(sk)->num); + return packet_do_bind(sk, name, 0, READ_ONCE(pkt_sk(sk)->num)); } static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) @@ -3277,7 +3277,7 @@ static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len return -EINVAL; return packet_do_bind(sk, NULL, sll->sll_ifindex, - sll->sll_protocol ? : pkt_sk(sk)->num); + sll->sll_protocol ? : READ_ONCE(pkt_sk(sk)->num)); } static struct proto packet_proto = { diff --git a/net/packet/diag.c b/net/packet/diag.c index d704c7bf51b20..a68a84574c739 100644 --- a/net/packet/diag.c +++ b/net/packet/diag.c @@ -143,7 +143,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, rp = nlmsg_data(nlh); rp->pdiag_family = AF_PACKET; rp->pdiag_type = sk->sk_type; - rp->pdiag_num = ntohs(po->num); + rp->pdiag_num = ntohs(READ_ONCE(po->num)); rp->pdiag_ino = sk_ino; sock_diag_save_cookie(sk, rp->pdiag_cookie); -- 2.39.2