From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7D18C433E0 for ; Mon, 29 Jun 2020 21:27:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6CCF208DB for ; Mon, 29 Jun 2020 21:27:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391139AbgF2V1t (ORCPT ); Mon, 29 Jun 2020 17:27:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729062AbgF2Smo (ORCPT ); Mon, 29 Jun 2020 14:42:44 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8FCDC033C15; Mon, 29 Jun 2020 11:26:31 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jpyUA-002DuT-71; Mon, 29 Jun 2020 18:26:30 +0000 From: Al Viro To: Linus Torvalds Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, David Miller , Tony Luck , Will Deacon Subject: [PATCH 16/41] arm64: sanitize compat_ptrace_write_user() Date: Mon, 29 Jun 2020 19:26:03 +0100 Message-Id: <20200629182628.529995-16-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200629182628.529995-1-viro@ZenIV.linux.org.uk> References: <20200629182349.GA2786714@ZenIV.linux.org.uk> <20200629182628.529995-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro don't bother with copy_regset_from_user() (not to mention set_fs()) Signed-off-by: Al Viro --- arch/arm64/kernel/ptrace.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index d5f3da5197a1..9f769e862f68 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1553,8 +1553,8 @@ static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off, static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off, compat_ulong_t val) { - int ret; - mm_segment_t old_fs = get_fs(); + struct pt_regs newregs = *task_pt_regs(tsk); + unsigned int idx = off / 4; if (off & 3 || off >= COMPAT_USER_SZ) return -EIO; @@ -1562,14 +1562,25 @@ static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off, if (off >= sizeof(compat_elf_gregset_t)) return 0; - set_fs(KERNEL_DS); - ret = copy_regset_from_user(tsk, &user_aarch32_view, - REGSET_COMPAT_GPR, off, - sizeof(compat_ulong_t), - &val); - set_fs(old_fs); + switch (idx) { + case 15: + newregs.pc = val; + break; + case 16: + newregs.pstate = compat_psr_to_pstate(val); + break; + case 17: + newregs.orig_x0 = val; + break; + default: + newregs.regs[idx] = val; + } + + if (!valid_user_regs(&newregs.user_regs, tsk)) + return -EINVAL; - return ret; + *task_pt_regs(tsk) = newregs; + return 0; } #ifdef CONFIG_HAVE_HW_BREAKPOINT -- 2.11.0