From owner-svn-src-head@freebsd.org Mon May 7 21:32:09 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7261BFBD966; Mon, 7 May 2018 21:32:09 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 2066D72D67; Mon, 7 May 2018 21:32:09 +0000 (UTC) (envelope-from mjg@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 1B3C020EF4; Mon, 7 May 2018 21:32:09 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id w47LW8ww034908; Mon, 7 May 2018 21:32:08 GMT (envelope-from mjg@FreeBSD.org) Received: (from mjg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w47LW8RE034907; Mon, 7 May 2018 21:32:08 GMT (envelope-from mjg@FreeBSD.org) Message-Id: <201805072132.w47LW8RE034907@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org using -f From: Mateusz Guzik Date: Mon, 7 May 2018 21:32:08 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r333337 - head/sys/amd64/amd64 X-SVN-Group: head X-SVN-Commit-Author: mjg X-SVN-Commit-Paths: head/sys/amd64/amd64 X-SVN-Commit-Revision: 333337 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: 2.1.25 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: Mon, 07 May 2018 21:32:09 -0000 Author: mjg Date: Mon May 7 21:32:08 2018 New Revision: 333337 URL: https://svnweb.freebsd.org/changeset/base/333337 Log: amd64: stop asserting params != NULL in the syscall path The parameter is effectively controllable by userspace. It does not matter what it is set to as it is being passed to copyin - worst case the operation will just fail. While here stop computing it unless it is going to be used. Noted by: dillon@backplane.com Modified: head/sys/amd64/amd64/trap.c Modified: head/sys/amd64/amd64/trap.c ============================================================================== --- head/sys/amd64/amd64/trap.c Mon May 7 21:26:05 2018 (r333336) +++ head/sys/amd64/amd64/trap.c Mon May 7 21:32:08 2018 (r333337) @@ -886,7 +886,6 @@ cpu_fetch_syscall_args(struct thread *td) reg = 0; regcnt = 6; - params = (caddr_t)frame->tf_rsp + sizeof(register_t); sa->code = frame->tf_rax; if (sa->code == SYS_syscall || sa->code == SYS___syscall) { @@ -910,7 +909,7 @@ cpu_fetch_syscall_args(struct thread *td) argp += reg; memcpy(sa->args, argp, sizeof(sa->args[0]) * 6); if (sa->narg > regcnt) { - KASSERT(params != NULL, ("copyin args with no params!")); + params = (caddr_t)frame->tf_rsp + sizeof(register_t); error = copyin(params, &sa->args[regcnt], (sa->narg - regcnt) * sizeof(sa->args[0])); }