From owner-freebsd-bugs@FreeBSD.ORG Tue Mar 25 17:20:04 2008 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 6E7C41065674 for ; Tue, 25 Mar 2008 17:20:04 +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 5A0858FC1C for ; Tue, 25 Mar 2008 17:20:04 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id m2PHK498073120 for ; Tue, 25 Mar 2008 17:20:04 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.2/8.14.1/Submit) id m2PHK43D073119; Tue, 25 Mar 2008 17:20:04 GMT (envelope-from gnats) Resent-Date: Tue, 25 Mar 2008 17:20:04 GMT Resent-Message-Id: <200803251720.m2PHK43D073119@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, Jari Kirma Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5283C106566B for ; Tue, 25 Mar 2008 17:17:42 +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 4F7088FC20 for ; Tue, 25 Mar 2008 17:17:42 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.14.2/8.14.2) with ESMTP id m2PHHTjP033226 for ; Tue, 25 Mar 2008 17:17:29 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.14.2/8.14.1/Submit) id m2PHHT3E033225; Tue, 25 Mar 2008 17:17:29 GMT (envelope-from nobody) Message-Id: <200803251717.m2PHHT3E033225@www.freebsd.org> Date: Tue, 25 Mar 2008 17:17:29 GMT From: Jari Kirma To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/122082: NULL pointer dereference in in_pcbdrop 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, 25 Mar 2008 17:20:04 -0000 >Number: 122082 >Category: kern >Synopsis: NULL pointer dereference in in_pcbdrop >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 Mar 25 17:20:03 UTC 2008 >Closed-Date: >Last-Modified: >Originator: Jari Kirma >Release: 7.0-STABLE >Organization: Helsinki University of Technology >Environment: FreeBSD kirma.fi 7.0-STABLE FreeBSD 7.0-STABLE #3: Fri Mar 14 12:01:00 EET 2008 root@example.com:/usr/obj/usr/src/sys/VULCAN i386 >Description: According to two kernel crash dumps, it dies on NULL pointer dereference on in_pcbdrop. Specifically this occurs on LIST_REMOVE below: if (LIST_FIRST(&phd->phd_pcblist) == NULL) { LIST_REMOVE(phd, phd_hash); free(phd, M_PCB); } Even more specifically, this occurs on "(elm)->field.le_prev = LIST_NEXT((elm), field);" below: #define LIST_REMOVE(elm, field) do { \ QMD_LIST_CHECK_NEXT(elm, field); \ QMD_LIST_CHECK_PREV(elm, field); \ if (LIST_NEXT((elm), field) != NULL) \ LIST_NEXT((elm), field)->field.le_prev = \ (elm)->field.le_prev; \ *(elm)->field.le_prev = LIST_NEXT((elm), field); \ TRASHIT((elm)->field.le_next); \ TRASHIT((elm)->field.le_prev); \ } while (0) Obviously this occurs when phd->phd_hash->le_prev is NULL: (kgdb) p *phd $8 = {phd_hash = {le_next = 0x0, le_prev = 0x0}, phd_pcblist = { lh_first = 0x0}, phd_port = 0} The backtrace is essentially the same for both "clean" crashes I've seen: (kgdb) bt #0 doadump () at pcpu.h:195 #1 0xc05536e1 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:409 #2 0xc05539b4 in panic (fmt=Variable "fmt" is not available. ) at /usr/src/sys/kern/kern_shutdown.c:563 #3 0xc0767cf4 in trap_fatal (frame=0xe7135ba4, eva=0) at /usr/src/sys/i386/i386/trap.c:899 #4 0xc0767f44 in trap_pfault (frame=0xe7135ba4, usermode=0, eva=0) at /usr/src/sys/i386/i386/trap.c:812 #5 0xc07688aa in trap (frame=0xe7135ba4) at /usr/src/sys/i386/i386/trap.c:490 #6 0xc075025b in calltrap () at /usr/src/sys/i386/i386/exception.s:139 #7 0xc0600027 in in_pcbdrop (inp=0xcd4db0b4) at /usr/src/sys/netinet/in_pcb.c:758 #8 0xc066b53e in tcp_twclose (tw=0xcd1c8514, reuse=0) at /usr/src/sys/netinet/tcp_timewait.c:477 #9 0xc066b74e in tcp_tw_2msl_scan (reuse=0) at /usr/src/sys/netinet/tcp_timewait.c:644 #10 0xc066a31c in tcp_slowtimo () at /usr/src/sys/netinet/tcp_timer.c:129 #11 0xc059c19b in pfslowtimo (arg=0x0) at /usr/src/sys/kern/uipc_domain.c:459 #12 0xc05650b1 in softclock (dummy=0x0) at /usr/src/sys/kern/kern_timeout.c:274 #13 0xc0537b22 in ithread_loop (arg=0xc6bae6a0) at /usr/src/sys/kern/kern_intr.c:1036 #14 0xc05349e1 in fork_exit (callout=0xc0537981 , arg=0xc6bae6a0, frame=0xe7135d38) at /usr/src/sys/kern/kern_fork.c:781 #15 0xc07502d0 in fork_trampoline () at /usr/src/sys/i386/i386/exception.s:205 The system experiencing this problem is a quad-core Intel system with nvidia display adapter (and associated drivers). >How-To-Repeat: Seems to occur from time to time when using a web browser, probably when HTTP server closes a socket from the other end, since the crash seems to occur a moment after successfully loading a web page. >Fix: >Release-Note: >Audit-Trail: >Unformatted: