From patchwork Wed Nov 24 02:14:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Iwashima, Kuniyuki" X-Patchwork-Id: 12635853 X-Patchwork-Delegate: kuba@kernel.org 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 1C125C433EF for ; Wed, 24 Nov 2021 02:15:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240686AbhKXCSS (ORCPT ); Tue, 23 Nov 2021 21:18:18 -0500 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:19620 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232959AbhKXCSR (ORCPT ); Tue, 23 Nov 2021 21:18:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.co.jp; i=@amazon.co.jp; q=dns/txt; s=amazon201209; t=1637720108; x=1669256108; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EqucDFPyc9mIcEo9jR7KPPeyftAB90WDdEFlqpHePLc=; b=TkFY5yUYn2E3yh7gGFUPQ9MkVl728CTr63j9Bodgfs1Plpummn9m+ukq wPwDNgQrX9nwTsiL2+5FFuIGOK7fDGB28+a508q3Y5dQ/Hg3HDSwOmHRD 6HBOusegdauIZXcS35Af9r1HqO+Nsd3SceKqw1B/HQYoU02UQCVDcOwkQ A=; X-IronPort-AV: E=Sophos;i="5.87,258,1631577600"; d="scan'208";a="157432669" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-pdx-2c-5c4a15b1.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-6002.iad6.amazon.com with ESMTP; 24 Nov 2021 02:15:07 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan3.pdx.amazon.com [10.236.137.198]) by email-inbound-relay-pdx-2c-5c4a15b1.us-west-2.amazon.com (Postfix) with ESMTPS id E4F5D41FAF; Wed, 24 Nov 2021 02:15:06 +0000 (UTC) Received: from EX13D04ANC001.ant.amazon.com (10.43.157.89) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Wed, 24 Nov 2021 02:15:06 +0000 Received: from 88665a182662.ant.amazon.com (10.43.161.102) by EX13D04ANC001.ant.amazon.com (10.43.157.89) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Wed, 24 Nov 2021 02:15:02 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Jakub Kicinski CC: Al Viro , Eric Dumazet , Kuniyuki Iwashima , Kuniyuki Iwashima , Benjamin Herrenschmidt , Subject: [PATCH v3 net-next 01/13] af_unix: Use offsetof() instead of sizeof(). Date: Wed, 24 Nov 2021 11:14:19 +0900 Message-ID: <20211124021431.48956-2-kuniyu@amazon.co.jp> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211124021431.48956-1-kuniyu@amazon.co.jp> References: <20211124021431.48956-1-kuniyu@amazon.co.jp> MIME-Version: 1.0 X-Originating-IP: [10.43.161.102] X-ClientProxiedBy: EX13D03UWA004.ant.amazon.com (10.43.160.250) To EX13D04ANC001.ant.amazon.com (10.43.157.89) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org The length of the AF_UNIX socket address contains an offset to the member sun_path of struct sockaddr_un. Currently, the preceding member is just sun_family, and its type is sa_family_t and resolved to short. Therefore, the offset is represented by sizeof(short). However, it is not clear and fragile to changes in struct sockaddr_storage or sockaddr_un. This commit makes it clear and robust by rewriting sizeof() with offsetof(). Signed-off-by: Kuniyuki Iwashima --- net/unix/af_unix.c | 19 ++++++++++++------- net/unix/diag.c | 3 ++- 2 files changed, 14 insertions(+), 8 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 54e5553a150e..19b3edac8712 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -231,7 +231,8 @@ static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp { *hashp = 0; - if (len <= sizeof(short) || len > sizeof(*sunaddr)) + if (len <= offsetof(struct sockaddr_un, sun_path) || + len > sizeof(*sunaddr)) return -EINVAL; if (!sunaddr || sunaddr->sun_family != AF_UNIX) return -EINVAL; @@ -244,7 +245,8 @@ static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp * kernel address buffer. */ ((char *)sunaddr)[len] = 0; - len = strlen(sunaddr->sun_path)+1+sizeof(short); + len = strlen(sunaddr->sun_path) + + offsetof(struct sockaddr_un, sun_path) + 1; return len; } @@ -966,7 +968,8 @@ static int unix_autobind(struct socket *sock) goto out; err = -ENOMEM; - addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL); + addr = kzalloc(sizeof(*addr) + + offsetof(struct sockaddr_un, sun_path) + 16, GFP_KERNEL); if (!addr) goto out; @@ -974,7 +977,8 @@ static int unix_autobind(struct socket *sock) refcount_set(&addr->refcnt, 1); retry: - addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short); + addr->len = sprintf(addr->name->sun_path + 1, "%05x", ordernum) + + offsetof(struct sockaddr_un, sun_path) + 1; addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0)); addr->hash ^= sk->sk_type; @@ -1156,7 +1160,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) sunaddr->sun_family != AF_UNIX) return -EINVAL; - if (addr_len == sizeof(short)) + if (addr_len == offsetof(struct sockaddr_un, sun_path)) return unix_autobind(sock); err = unix_mkname(sunaddr, addr_len, &hash); @@ -1600,7 +1604,7 @@ static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int peer) if (!addr) { sunaddr->sun_family = AF_UNIX; sunaddr->sun_path[0] = 0; - err = sizeof(short); + err = offsetof(struct sockaddr_un, sun_path); } else { err = addr->len; memcpy(sunaddr, addr->name, addr->len); @@ -3231,7 +3235,8 @@ static int unix_seq_show(struct seq_file *seq, void *v) seq_putc(seq, ' '); i = 0; - len = u->addr->len - sizeof(short); + len = u->addr->len - + offsetof(struct sockaddr_un, sun_path); if (!UNIX_ABSTRACT(s)) len--; else { diff --git a/net/unix/diag.c b/net/unix/diag.c index 7e7d7f45685a..db555f267407 100644 --- a/net/unix/diag.c +++ b/net/unix/diag.c @@ -19,7 +19,8 @@ static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb) if (!addr) return 0; - return nla_put(nlskb, UNIX_DIAG_NAME, addr->len - sizeof(short), + return nla_put(nlskb, UNIX_DIAG_NAME, + addr->len - offsetof(struct sockaddr_un, sun_path), addr->name->sun_path); }