Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933332AbdC3KO5 (ORCPT ); Thu, 30 Mar 2017 06:14:57 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54506 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932932AbdC3KNE (ORCPT ); Thu, 30 Mar 2017 06:13:04 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Martin , Linus Torvalds Subject: [PATCH 4.10 10/17] mips/ptrace: Preserve previous registers for short regset write Date: Thu, 30 Mar 2017 12:00:25 +0200 Message-Id: <20170330095927.390470263@linuxfoundation.org> X-Mailer: git-send-email 2.12.1 In-Reply-To: <20170330095925.918515862@linuxfoundation.org> References: <20170330095925.918515862@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1102 Lines: 32 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Martin commit d614fd58a2834cfe4efa472c33c8f3ce2338b09b upstream. Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. Signed-off-by: Dave Martin Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/mips/kernel/ptrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -485,7 +485,8 @@ static int fpr_set(struct task_struct *t &target->thread.fpu, 0, sizeof(elf_fpregset_t)); - for (i = 0; i < NUM_FPU_REGS; i++) { + BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t)); + for (i = 0; i < NUM_FPU_REGS && count >= sizeof(elf_fpreg_t); i++) { err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpr_val, i * sizeof(elf_fpreg_t), (i + 1) * sizeof(elf_fpreg_t));