From owner-svn-src-head@freebsd.org Wed Oct 23 17:58:20 2019 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 8B58515A0D9; Wed, 23 Oct 2019 17:58:20 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46yylw2pLrz4V52; Wed, 23 Oct 2019 17:58:20 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 43B92398; Wed, 23 Oct 2019 17:58:20 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x9NHwKFj079094; Wed, 23 Oct 2019 17:58:20 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x9NHwK3Z079093; Wed, 23 Oct 2019 17:58:20 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201910231758.x9NHwK3Z079093@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Wed, 23 Oct 2019 17:58:20 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r353956 - head/sys/vm X-SVN-Group: head X-SVN-Commit-Author: markj X-SVN-Commit-Paths: head/sys/vm X-SVN-Commit-Revision: 353956 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Oct 2019 17:58:20 -0000 Author: markj Date: Wed Oct 23 17:58:19 2019 New Revision: 353956 URL: https://svnweb.freebsd.org/changeset/base/353956 Log: Verify identity after checking for WAITFAIL in vm_page_busy_acquire(). A caller that does not guarantee that a page's identity won't change while sleeping for a busy lock must specify either NOWAIT or WAITFAIL. Reported by: syzkaller Reviewed by: alc, kib Discussed with: jeff Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22124 Modified: head/sys/vm/vm_page.c Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Wed Oct 23 17:53:20 2019 (r353955) +++ head/sys/vm/vm_page.c Wed Oct 23 17:58:19 2019 (r353956) @@ -900,9 +900,11 @@ vm_page_busy_acquire(vm_page_t m, int allocflags) (allocflags & VM_ALLOC_SBUSY) != 0, locked); if (locked) VM_OBJECT_WLOCK(obj); - MPASS(m->object == obj || m->object == NULL); if ((allocflags & VM_ALLOC_WAITFAIL) != 0) return (FALSE); + KASSERT(m->object == obj || m->object == NULL, + ("vm_page_busy_acquire: page %p does not belong to %p", + m, obj)); } }