From owner-svn-src-head@freebsd.org Thu Sep 26 15:35:36 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 06D0012A2C0; Thu, 26 Sep 2019 15:35:36 +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 46fJsg6NYLz4NyK; Thu, 26 Sep 2019 15:35:35 +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 BEF33245E; Thu, 26 Sep 2019 15:35:35 +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 x8QFZZPo049915; Thu, 26 Sep 2019 15:35:35 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x8QFZZnk049914; Thu, 26 Sep 2019 15:35:35 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201909261535.x8QFZZnk049914@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Thu, 26 Sep 2019 15:35:35 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r352748 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: markj X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 352748 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: Thu, 26 Sep 2019 15:35:36 -0000 Author: markj Date: Thu Sep 26 15:35:35 2019 New Revision: 352748 URL: https://svnweb.freebsd.org/changeset/base/352748 Log: Fix handling of invalid pages in exec_map_first_page(). exec_map_first_page() would unconditionally free an unbacked, invalid page from the executable image. However, it is possible that the page is wired, in which case it is incorrect to free the page, so check for additional wirings first. Reported by: syzkaller Tested by: pho Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21767 Modified: head/sys/kern/kern_exec.c Modified: head/sys/kern/kern_exec.c ============================================================================== --- head/sys/kern/kern_exec.c Thu Sep 26 15:32:28 2019 (r352747) +++ head/sys/kern/kern_exec.c Thu Sep 26 15:35:35 2019 (r352748) @@ -981,8 +981,10 @@ exec_map_first_page(struct image_params *imgp) if (ma[0]->valid != VM_PAGE_BITS_ALL) { vm_page_xbusy(ma[0]); if (!vm_pager_has_page(object, 0, NULL, &after)) { - vm_page_unwire_noq(ma[0]); - vm_page_free(ma[0]); + if (vm_page_unwire_noq(ma[0])) + vm_page_free(ma[0]); + else + vm_page_xunbusy(ma[0]); VM_OBJECT_WUNLOCK(object); return (EIO); } @@ -1006,9 +1008,16 @@ exec_map_first_page(struct image_params *imgp) initial_pagein = i; rv = vm_pager_get_pages(object, ma, initial_pagein, NULL, NULL); if (rv != VM_PAGER_OK) { - vm_page_unwire_noq(ma[0]); - for (i = 0; i < initial_pagein; i++) - vm_page_free(ma[i]); + if (vm_page_unwire_noq(ma[0])) + vm_page_free(ma[0]); + else + vm_page_xunbusy(ma[0]); + for (i = 1; i < initial_pagein; i++) { + if (!vm_page_wired(ma[i])) + vm_page_free(ma[i]); + else + vm_page_xunbusy(ma[i]); + } VM_OBJECT_WUNLOCK(object); return (EIO); }