From owner-freebsd-bugs@FreeBSD.ORG Tue Nov 20 16:30:02 2007 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 40D6B16A417 for ; Tue, 20 Nov 2007 16:30:02 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 31C6613C47E for ; Tue, 20 Nov 2007 16:30:02 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.1/8.14.1) with ESMTP id lAKGU1cJ030757 for ; Tue, 20 Nov 2007 16:30:02 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.1/8.14.1/Submit) id lAKGU1t6030754; Tue, 20 Nov 2007 16:30:01 GMT (envelope-from gnats) Resent-Date: Tue, 20 Nov 2007 16:30:01 GMT Resent-Message-Id: <200711201630.lAKGU1t6030754@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Ivan Shcheklein Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0956F16A417 for ; Tue, 20 Nov 2007 16:23:37 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [IPv6:2001:4f8:fff6::21]) by mx1.freebsd.org (Postfix) with ESMTP id 0A13D13C43E for ; Tue, 20 Nov 2007 16:23:37 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.14.1/8.14.1) with ESMTP id lAKGMrao098211 for ; Tue, 20 Nov 2007 16:22:53 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.14.1/8.14.1/Submit) id lAKGMr7e098210; Tue, 20 Nov 2007 16:22:53 GMT (envelope-from nobody) Message-Id: <200711201622.lAKGMr7e098210@www.freebsd.org> Date: Tue, 20 Nov 2007 16:22:53 GMT From: Ivan Shcheklein To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/118153: [fix] "semprt" can be invalid after wakeup in the semop() X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Nov 2007 16:30:02 -0000 >Number: 118153 >Category: kern >Synopsis: [fix] "semprt" can be invalid after wakeup in the semop() >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Tue Nov 20 16:30:01 UTC 2007 >Closed-Date: >Last-Modified: >Originator: Ivan Shcheklein >Release: FREEBSD-6.2 >Organization: ISP RAS >Environment: FreeBSD 6.2-RELEASE i386 >Description: Fistly, sorry for the my previous post of this bug: http://lists.freebsd.org/pipermail/freebsd-bugs/2007-November/026847.html I didn't know about the better way to submit bugs. I think, it can be removed or marked as duplicate to this one. The buf itself is the following. In sysv_sem.c::1173 we have: /* ... semaphores wakes up ... */ if (sopptr->sem_op == 0) semptr->semzcnt--; else semptr->semncnt--; Used here "semptr" after wakeup can be invalid due to "semakptr->u.sem_base" can be changed during semaphore sleeping. (For example it can be changed by removing another semaphore). >How-To-Repeat: >Fix: The solution for this problem is quiet obvious. We must use "semakptr" to get new "semptr". For example (possibly it can be written better): if (sopptr->sem_op == 0) (&semakptr->u.sem_base[sopptr->sem_num])->semzcnt--; else (&semakptr->u.sem_base[sopptr->sem_num])->semncnt--; >Release-Note: >Audit-Trail: >Unformatted: