From patchwork Sat Jan 24 22:49:30 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Vegard Nossum X-Patchwork-Id: 20183 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id D5F90DE0CB for ; Sun, 25 Jan 2009 09:54:29 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751882AbZAXWyV (ORCPT ); Sat, 24 Jan 2009 17:54:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751787AbZAXWyU (ORCPT ); Sat, 24 Jan 2009 17:54:20 -0500 Received: from mail-ew0-f10.google.com ([209.85.219.10]:61183 "EHLO mail-ew0-f10.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751606AbZAXWyT (ORCPT ); Sat, 24 Jan 2009 17:54:19 -0500 X-Greylist: delayed 436 seconds by postgrey-1.27 at vger.kernel.org; Sat, 24 Jan 2009 17:54:18 EST Received: by ewy3 with SMTP id 3so272713ewy.13 for ; Sat, 24 Jan 2009 14:54:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :message-id:mime-version:content-type:content-disposition :content-transfer-encoding:user-agent; bh=zAgjOdqwAr0Gloi7kpt+IGuF9jjsWNX344b8Kl44Bxs=; b=P46+I1tcZ8HnhQbFIFsxi3vVn2ZSVCYfjAGYP4v8wdylE0bvSOGXxzXERwRQDdGBps zp5reKBQGCmdQX4IPtIQ/hY5++AprraOg2K+RcjPWoM4ZAqyIwpH14cdIZ0ziwl7Ym3Q ttez3i0wSg6Lj0xvX5LjE0osSwYT85MURJxyc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:content-transfer-encoding:user-agent; b=RwSszNkZZbjrH7A/OY60/IAG9Hz+hTceLfwIX0ltohOZKVSE6JIQtnmSwD7T+A01dc r+cJ9BKjO7oBIrHrsCaLQq303bVP22FHqLBQsvRm3fXy90GKJqQWdpB07YG8C/ArqHEz DWXBlBydJ+haIi5YKryxzOQIUEcK2Bm2fWZrE= Received: by 10.210.137.17 with SMTP id k17mr2858996ebd.9.1232837221399; Sat, 24 Jan 2009 14:47:01 -0800 (PST) Received: from localhost.localdomain (cm-84.209.125.101.getinternet.no [84.209.125.101]) by mx.google.com with ESMTPS id f6sm35175544nfh.79.2009.01.24.14.46.58 (version=SSLv3 cipher=RC4-MD5); Sat, 24 Jan 2009 14:47:00 -0800 (PST) Date: Sat, 24 Jan 2009 23:49:30 +0100 From: Vegard Nossum To: "David S. Miller" Cc: Martin =?utf-8?Q?MOKREJ=C5=A0?= , netdev@vger.kernel.org Subject: [PATCH] net: fix setsockopt() locking errors Message-ID: <20090124224930.GA4456@localhost.localdomain> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, This survives basic testing here, but I don't know what that counts for when I couldn't reproduce the lockdep report in the first place. Please review. Vegard From cc8bcd1c4fd219a31d6d191aefa4b4b57dadb9b0 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Sat, 24 Jan 2009 22:44:16 +0100 Subject: [PATCH] net: fix setsockopt() locking errors MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Martin MOKREJŠ reported: > ======================================================= > [ INFO: possible circular locking dependency detected ] > 2.6.29-rc2-git1 #1 > ------------------------------------------------------- > tcpdump/3734 is trying to acquire lock: > (&mm->mmap_sem){----}, at: [] might_fault+0x30/0x6b > > but task is already holding lock: > (sk_lock-AF_PACKET){--..}, at: [] sock_setsockopt+0x12b/0x4a4 > > which lock already depends on the new lock. It turns out that sock_setsockopt() is calling copy_from_user() while holding the lock on the socket. We fix it by splitting the ioctl code so that one switch handles the ioctls that have their own code for reading from userspace, and one switch handles the cases that require no additional reading. Reported-by: Martin MOKREJŠ Signed-off-by: Vegard Nossum --- net/core/sock.c | 134 +++++++++++++++++++++++++++++++++++------------------- 1 files changed, 87 insertions(+), 47 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index f3a0d08..6bd618d 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -424,6 +424,80 @@ out: return ret; } +static int sock_linger(struct sock *sk, char __user *optval, int optlen) +{ + struct linger ling; + + if (optlen < sizeof(ling)) + return -EINVAL; /* 1003.1g */ + if (copy_from_user(&ling, optval, sizeof(ling))) + return -EFAULT; + + lock_sock(sk); + + if (!ling.l_onoff) + sock_reset_flag(sk, SOCK_LINGER); + else { +#if (BITS_PER_LONG == 32) + if ((unsigned int) ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ) + sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT; + else +#endif + sk->sk_lingertime = (unsigned int) ling.l_linger * HZ; + sock_set_flag(sk, SOCK_LINGER); + } + + release_sock(sk); + + return 0; +} + +static int sock_set_rcvtimeo(struct sock *sk, char __user *optval, int optlen) +{ + int ret; + long rcvtimeo; + + ret = sock_set_timeout(&rcvtimeo, optval, optlen); + + lock_sock(sk); + sk->sk_rcvtimeo = rcvtimeo; + release_sock(sk); + + return ret; +} + +static int sock_set_sndtimeo(struct sock *sk, char __user *optval, int optlen) +{ + int ret; + long sndtimeo; + + ret = sock_set_timeout(&sndtimeo, optval, optlen); + + lock_sock(sk); + sk->sk_sndtimeo = sndtimeo; + release_sock(sk); + + return ret; +} + +static int sock_attach_filter(struct sock *sk, char __user *optval, int optlen) +{ + int ret; + struct sock_fprog fprog; + + if (optlen != sizeof(struct sock_fprog)) + return -EINVAL; + + if (copy_from_user(&fprog, optval, sizeof(fprog))) + return -EFAULT; + + lock_sock(sk); + ret = sk_attach_filter(&fprog, sk); + release_sock(sk); + + return ret; +} + static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool) { if (valbool) @@ -440,18 +514,27 @@ static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool) int sock_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen) { - struct sock *sk=sock->sk; + struct sock *sk = sock->sk; int val; int valbool; - struct linger ling; int ret = 0; /* - * Options without arguments + * Options with special locking requirements */ - if (optname == SO_BINDTODEVICE) + switch (optname) { + case SO_BINDTODEVICE: return sock_bindtodevice(sk, optval, optlen); + case SO_LINGER: + return sock_linger(sk, optval, optlen); + case SO_RCVTIMEO: + return sock_set_rcvtimeo(sk, optval, optlen); + case SO_SNDTIMEO: + return sock_set_sndtimeo(sk, optval, optlen); + case SO_ATTACH_FILTER: + return sock_attach_filter(sk, optval, optlen); + } if (optlen < sizeof(int)) return -EINVAL; @@ -573,28 +656,6 @@ set_rcvbuf: ret = -EPERM; break; - case SO_LINGER: - if (optlen < sizeof(ling)) { - ret = -EINVAL; /* 1003.1g */ - break; - } - if (copy_from_user(&ling,optval,sizeof(ling))) { - ret = -EFAULT; - break; - } - if (!ling.l_onoff) - sock_reset_flag(sk, SOCK_LINGER); - else { -#if (BITS_PER_LONG == 32) - if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ) - sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT; - else -#endif - sk->sk_lingertime = (unsigned int)ling.l_linger * HZ; - sock_set_flag(sk, SOCK_LINGER); - } - break; - case SO_BSDCOMPAT: sock_warn_obsolete_bsdism("setsockopt"); break; @@ -627,27 +688,6 @@ set_rcvbuf: sk->sk_rcvlowat = val ? : 1; break; - case SO_RCVTIMEO: - ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen); - break; - - case SO_SNDTIMEO: - ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen); - break; - - case SO_ATTACH_FILTER: - ret = -EINVAL; - if (optlen == sizeof(struct sock_fprog)) { - struct sock_fprog fprog; - - ret = -EFAULT; - if (copy_from_user(&fprog, optval, sizeof(fprog))) - break; - - ret = sk_attach_filter(&fprog, sk); - } - break; - case SO_DETACH_FILTER: ret = sk_detach_filter(sk); break;