From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: [PATCH netdev] "wrong timeout value" in sk_wait_data() Date: Thu, 24 May 2007 08:22:03 +0400 Message-ID: <465512EB.4000808@sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit To: "David S. Miller" , netdev@vger.kernel.org, Andrew Morton , Linux Kernel Mailing List , devel@openvz.org Return-path: Received: from mailhub.sw.ru ([195.214.233.200]:13139 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759198AbXEXE1S (ORCPT ); Thu, 24 May 2007 00:27:18 -0400 Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org sys_setsockopt() do not check properly timeout values for SO_RCVTIMEO/SO_SNDTIMEO, for example it's possible to set negative timeout values. POSIX do not defines behaviour for sys_setsockopt in case negative timeouts, but requires that setsockopt() shall fail with -EDOM if the send and receive timeout values are too big to fit into the timeout fields in the socket structure. In current implementation negative timeout can lead to error messages like "schedule_timeout: wrong timeout value". Proposed patch: - checks tv_usec and returns -EDOM if it is wrong - do not allows to set negative timeout values (sets 0 instead) and outputs ratelimited information message about such attempts. Signed-Off-By: Vasily Averin diff --git a/net/core/sock.c b/net/core/sock.c index 22183c2..27d7a46 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -206,7 +206,19 @@ static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen) return -EINVAL; if (copy_from_user(&tv, optval, sizeof(tv))) return -EFAULT; - + if (tv.tv_usec < 0 || tv.tv_usec >= 1000000) + return -EDOM; + + if (tv.tv_sec < 0) { + static int warned = 0; + *timeo_p = 0; + if (warned < 10 && net_ratelimit()) + warned++; + printk(KERN_INFO "sock_set_timeout: `%s' (pid %d) " + "tries to set negative timeout\n", + current->comm, current->pid); + return 0; + } *timeo_p = MAX_SCHEDULE_TIMEOUT; if (tv.tv_sec == 0 && tv.tv_usec == 0) return 0;