From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41500 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934411AbeAJM1J (ORCPT ); Wed, 10 Jan 2018 07:27:09 -0500 Subject: Patch "MIPS: Guard against any partial write attempt with PTRACE_SETREGSET" has been added to the 4.14-stable tree To: macro@mips.com, Dave.Martin@arm.com, Paul.Burton@mips.com, alex@alex-smith.me.uk, gregkh@linuxfoundation.org, james.hogan@mips.com, ralf@linux-mips.org Cc: , From: Date: Wed, 10 Jan 2018 13:19:17 +0100 Message-ID: <1515586757834@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled MIPS: Guard against any partial write attempt with PTRACE_SETREGSET to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From dc24d0edf33c3e15099688b6bbdf7bdc24bf6e91 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Mon, 11 Dec 2017 22:52:15 +0000 Subject: MIPS: Guard against any partial write attempt with PTRACE_SETREGSET From: Maciej W. Rozycki commit dc24d0edf33c3e15099688b6bbdf7bdc24bf6e91 upstream. Complement commit d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") and ensure that no partial register write attempt is made with PTRACE_SETREGSET, as we do not preinitialize any temporaries used to hold incoming register data and consequently random data could be written. It is the responsibility of the caller, such as `ptrace_regset', to arrange for writes to span whole registers only, so here we only assert that it has indeed happened. Signed-off-by: Maciej W. Rozycki Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: James Hogan Cc: Paul Burton Cc: Alex Smith Cc: Dave Martin Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17926/ Signed-off-by: Ralf Baechle Signed-off-by: Greg Kroah-Hartman --- arch/mips/kernel/ptrace.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -507,7 +507,15 @@ static int fpr_set_msa(struct task_struc return 0; } -/* Copy the supplied NT_PRFPREG buffer to the floating-point context. */ +/* + * Copy the supplied NT_PRFPREG buffer to the floating-point context. + * + * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0', + * which is supposed to have been guaranteed by the kernel before + * calling us, e.g. in `ptrace_regset'. We enforce that requirement, + * so that we can safely avoid preinitializing temporaries for + * partial register writes. + */ static int fpr_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, @@ -515,6 +523,8 @@ static int fpr_set(struct task_struct *t { int err; + BUG_ON(count % sizeof(elf_fpreg_t)); + /* XXX fcr31 */ init_fp_ctx(target); Patches currently in stable-queue which might be from macro@mips.com are queue-4.14/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch queue-4.14/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch queue-4.14/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch queue-4.14/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch queue-4.14/mips-factor-out-nt_prfpreg-regset-access-helpers.patch queue-4.14/mips-validate-pr_set_fp_mode-prctl-2-requests-against-the-abi-of-the-task.patch queue-4.14/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch