From owner-freebsd-bugs@FreeBSD.ORG Fri Dec 27 16:20:01 2013 Return-Path: Delivered-To: freebsd-bugs@smarthost.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 18F31FE7 for ; Fri, 27 Dec 2013 16:20:01 +0000 (UTC) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:1900:2254:206c::16:87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id CEC721AE8 for ; Fri, 27 Dec 2013 16:20:00 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.7/8.14.7) with ESMTP id rBRGK0bK069812 for ; Fri, 27 Dec 2013 16:20:00 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.7/8.14.7/Submit) id rBRGK0bc069811; Fri, 27 Dec 2013 16:20:00 GMT (envelope-from gnats) Resent-Date: Fri, 27 Dec 2013 16:20:00 GMT Resent-Message-Id: <201312271620.rBRGK0bc069811@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, Greg Becker Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 69F27C07 for ; Fri, 27 Dec 2013 16:13:44 +0000 (UTC) Received: from oldred.freebsd.org (oldred.freebsd.org [IPv6:2001:1900:2254:206a::50:4]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 560DC1AA4 for ; Fri, 27 Dec 2013 16:13:44 +0000 (UTC) Received: from oldred.freebsd.org ([127.0.1.6]) by oldred.freebsd.org (8.14.5/8.14.7) with ESMTP id rBRGDgOL068946 for ; Fri, 27 Dec 2013 16:13:42 GMT (envelope-from nobody@oldred.freebsd.org) Received: (from nobody@localhost) by oldred.freebsd.org (8.14.5/8.14.5/Submit) id rBRGDgN8068938; Fri, 27 Dec 2013 16:13:42 GMT (envelope-from nobody) Message-Id: <201312271613.rBRGDgN8068938@oldred.freebsd.org> Date: Fri, 27 Dec 2013 16:13:42 GMT From: Greg Becker To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Subject: kern/185232: Kernel page fault in jailed() via vn_stat() when using uio_td from nfsrv_read() X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Dec 2013 16:20:01 -0000 >Number: 185232 >Category: kern >Synopsis: Kernel page fault in jailed() via vn_stat() when using uio_td from nfsrv_read() >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Fri Dec 27 16:20:00 UTC 2013 >Closed-Date: >Last-Modified: >Originator: Greg Becker >Release: 9.2 >Organization: NetApp >Environment: FreeBSD perf-filer-1.stl.netapp.com 9.2-STABLE FreeBSD 9.2-STABLE #69 r259677M: Fri Dec 27 06:15:18 CST 2013 beckerg@perf-filer-1.stl.netapp.com:/usr/obj/usr/src/sys/PERFFILER1 amd64 >Description: I'm using a custom nullfs that calls vn_stat() from my null_read() function. The problem is, nfsrv_read() doesn't set uio_td, so my null_read() function gets whatever was on the caller's stack. >How-To-Repeat: >Fix: Either don't use uio_td when being called from nfssrv_read(), or set uio_td to NULL in nfssrv_read(). Patch attached with submission follows: Index: sys/nfsserver/nfs_serv.c =================================================================== --- sys/nfsserver/nfs_serv.c (revision 259677) +++ sys/nfsserver/nfs_serv.c (working copy) @@ -965,6 +965,7 @@ uiop->uio_resid = len; uiop->uio_rw = UIO_READ; uiop->uio_segflg = UIO_SYSSPACE; + uiop->uio_td = NULL; nh = nfsrv_sequential_heuristic(uiop, vp); ioflag |= nh->nh_seqcount << IO_SEQSHIFT; error = VOP_READ(vp, uiop, IO_NODELOCKED | ioflag, cred); >Release-Note: >Audit-Trail: >Unformatted: