From patchwork Tue Jul 30 05:51:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11064953 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 272B413A4 for ; Tue, 30 Jul 2019 05:53:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 18DFD28704 for ; Tue, 30 Jul 2019 05:53:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0CD9328714; Tue, 30 Jul 2019 05:53:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A341228704 for ; Tue, 30 Jul 2019 05:53:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729764AbfG3FxK (ORCPT ); Tue, 30 Jul 2019 01:53:10 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:44581 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728338AbfG3Fwh (ORCPT ); Tue, 30 Jul 2019 01:52:37 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id C4A9E1BF20E; Tue, 30 Jul 2019 05:52:31 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 01/14] mm, fs: Move randomize_stack_top from fs to mm Date: Tue, 30 Jul 2019 01:51:00 -0400 Message-Id: <20190730055113.23635-2-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This preparatory commit moves this function so that further introduction of generic topdown mmap layout is contained only in mm/util.c. Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain --- fs/binfmt_elf.c | 20 -------------------- include/linux/mm.h | 2 ++ mm/util.c | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+), 20 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index d4e11b2e04f6..cec3b4146440 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -670,26 +670,6 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, * libraries. There is no binary dependent code anywhere else. */ -#ifndef STACK_RND_MASK -#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ -#endif - -static unsigned long randomize_stack_top(unsigned long stack_top) -{ - unsigned long random_variable = 0; - - if (current->flags & PF_RANDOMIZE) { - random_variable = get_random_long(); - random_variable &= STACK_RND_MASK; - random_variable <<= PAGE_SHIFT; - } -#ifdef CONFIG_STACK_GROWSUP - return PAGE_ALIGN(stack_top) + random_variable; -#else - return PAGE_ALIGN(stack_top) - random_variable; -#endif -} - static int load_elf_binary(struct linux_binprm *bprm) { struct file *interpreter = NULL; /* to shut gcc up */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 0334ca97c584..ae0e5d241eb8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2351,6 +2351,8 @@ extern int install_special_mapping(struct mm_struct *mm, unsigned long addr, unsigned long len, unsigned long flags, struct page **pages); +unsigned long randomize_stack_top(unsigned long stack_top); + extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); extern unsigned long mmap_region(struct file *file, unsigned long addr, diff --git a/mm/util.c b/mm/util.c index e6351a80f248..15a4fb0f5473 100644 --- a/mm/util.c +++ b/mm/util.c @@ -16,6 +16,8 @@ #include #include #include +#include +#include #include @@ -293,6 +295,26 @@ int vma_is_stack_for_current(struct vm_area_struct *vma) return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t)); } +#ifndef STACK_RND_MASK +#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ +#endif + +unsigned long randomize_stack_top(unsigned long stack_top) +{ + unsigned long random_variable = 0; + + if (current->flags & PF_RANDOMIZE) { + random_variable = get_random_long(); + random_variable &= STACK_RND_MASK; + random_variable <<= PAGE_SHIFT; + } +#ifdef CONFIG_STACK_GROWSUP + return PAGE_ALIGN(stack_top) + random_variable; +#else + return PAGE_ALIGN(stack_top) - random_variable; +#endif +} + #if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) { From patchwork Tue Jul 30 05:51:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11064959 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E139414E5 for ; Tue, 30 Jul 2019 05:53:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D36E028704 for ; Tue, 30 Jul 2019 05:53:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C72D028714; Tue, 30 Jul 2019 05:53:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7EB4328704 for ; Tue, 30 Jul 2019 05:53:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727236AbfG3Fxo (ORCPT ); Tue, 30 Jul 2019 01:53:44 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:33621 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726133AbfG3Fxo (ORCPT ); Tue, 30 Jul 2019 01:53:44 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 8A9D220002; Tue, 30 Jul 2019 05:53:36 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 02/14] arm64: Make use of is_compat_task instead of hardcoding this test Date: Tue, 30 Jul 2019 01:51:01 -0400 Message-Id: <20190730055113.23635-3-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Each architecture has its own way to determine if a task is a compat task, by using is_compat_task in arch_mmap_rnd, it allows more genericity and then it prepares its moving to mm/. Signed-off-by: Alexandre Ghiti Acked-by: Catalin Marinas Acked-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain --- arch/arm64/mm/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index b050641b5139..bb0140afed66 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -43,7 +43,7 @@ unsigned long arch_mmap_rnd(void) unsigned long rnd; #ifdef CONFIG_COMPAT - if (test_thread_flag(TIF_32BIT)) + if (is_compat_task()) rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); else #endif From patchwork Tue Jul 30 05:51:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11064969 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0FF2713A0 for ; Tue, 30 Jul 2019 05:54:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 01F862870F for ; Tue, 30 Jul 2019 05:54:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E9C4728716; Tue, 30 Jul 2019 05:54:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A08172870F for ; Tue, 30 Jul 2019 05:54:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727860AbfG3Fys (ORCPT ); Tue, 30 Jul 2019 01:54:48 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:55753 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726205AbfG3Fys (ORCPT ); Tue, 30 Jul 2019 01:54:48 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id A580220003; Tue, 30 Jul 2019 05:54:42 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 03/14] arm64: Consider stack randomization for mmap base only when necessary Date: Tue, 30 Jul 2019 01:51:02 -0400 Message-Id: <20190730055113.23635-4-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Do not offset mmap base address because of stack randomization if current task does not want randomization. Note that x86 already implements this behaviour. Signed-off-by: Alexandre Ghiti Acked-by: Catalin Marinas Acked-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain --- arch/arm64/mm/mmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index bb0140afed66..e4acaead67de 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -54,7 +54,11 @@ unsigned long arch_mmap_rnd(void) static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) { unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = (STACK_RND_MASK << PAGE_SHIFT) + stack_guard_gap; + unsigned long pad = stack_guard_gap; + + /* Account for stack randomization if necessary */ + if (current->flags & PF_RANDOMIZE) + pad += (STACK_RND_MASK << PAGE_SHIFT); /* Values close to RLIM_INFINITY can overflow. */ if (gap + pad > gap) From patchwork Tue Jul 30 05:51:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11064979 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 375D013A0 for ; Tue, 30 Jul 2019 05:56:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2796928397 for ; Tue, 30 Jul 2019 05:56:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 18ECC284D2; Tue, 30 Jul 2019 05:56:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5FCDE28397 for ; Tue, 30 Jul 2019 05:55:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726876AbfG3Fzy (ORCPT ); Tue, 30 Jul 2019 01:55:54 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:60573 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725966AbfG3Fzy (ORCPT ); Tue, 30 Jul 2019 01:55:54 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 2E51020006; Tue, 30 Jul 2019 05:55:47 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti , Christoph Hellwig Subject: [PATCH v5 04/14] arm64, mm: Move generic mmap layout functions to mm Date: Tue, 30 Jul 2019 01:51:03 -0400 Message-Id: <20190730055113.23635-5-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP arm64 handles top-down mmap layout in a way that can be easily reused by other architectures, so make it available in mm. It then introduces a new config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other architectures to benefit from those functions. Note that this new config depends on MMU being enabled, if selected without MMU support, a warning will be thrown. Suggested-by: Christoph Hellwig Signed-off-by: Alexandre Ghiti Acked-by: Catalin Marinas Acked-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain --- arch/Kconfig | 10 ++++ arch/arm64/Kconfig | 1 + arch/arm64/include/asm/processor.h | 2 - arch/arm64/mm/mmap.c | 76 ----------------------------- kernel/sysctl.c | 6 ++- mm/util.c | 78 +++++++++++++++++++++++++++++- 6 files changed, 92 insertions(+), 81 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index a7b57dd42c26..a0bb6fa4d381 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -696,6 +696,16 @@ config HAVE_ARCH_COMPAT_MMAP_BASES and vice-versa 32-bit applications to call 64-bit mmap(). Required for applications doing different bitness syscalls. +# This allows to use a set of generic functions to determine mmap base +# address by giving priority to top-down scheme only if the process +# is not in legacy mode (compat task, unlimited stack size or +# sysctl_legacy_va_layout). +# Architecture that selects this option can provide its own version of: +# - STACK_RND_MASK +config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT + bool + depends on MMU + config HAVE_COPY_THREAD_TLS bool help diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3adcec05b1f6..14a194e63458 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -72,6 +72,7 @@ config ARM64 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG select ARCH_SUPPORTS_NUMA_BALANCING select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) select ARCH_HAS_UBSAN_SANITIZE_ALL diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 844e2964b0f5..65e2de00913f 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -281,8 +281,6 @@ static inline void spin_lock_prefetch(const void *ptr) "nop") : : "p" (ptr)); } -#define HAVE_ARCH_PICK_MMAP_LAYOUT - #endif extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */ diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index e4acaead67de..3028bacbc4e9 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -20,82 +20,6 @@ #include -/* - * Leave enough space between the mmap area and the stack to honour ulimit in - * the face of randomisation. - */ -#define MIN_GAP (SZ_128M) -#define MAX_GAP (STACK_TOP/6*5) - -static int mmap_is_legacy(struct rlimit *rlim_stack) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlim_stack->rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -unsigned long arch_mmap_rnd(void) -{ - unsigned long rnd; - -#ifdef CONFIG_COMPAT - if (is_compat_task()) - rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); - else -#endif - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - return rnd << PAGE_SHIFT; -} - -static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) -{ - unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = stack_guard_gap; - - /* Account for stack randomization if necessary */ - if (current->flags & PF_RANDOMIZE) - pad += (STACK_RND_MASK << PAGE_SHIFT); - - /* Values close to RLIM_INFINITY can overflow. */ - if (gap + pad > gap) - gap += pad; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(STACK_TOP - gap - rnd); -} - -/* - * This function, called very early during the creation of a new process VM - * image, sets up which VM layout function to use: - */ -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) -{ - unsigned long random_factor = 0UL; - - if (current->flags & PF_RANDOMIZE) - random_factor = arch_mmap_rnd(); - - /* - * Fall back to the standard layout if the personality bit is set, or - * if the expected stack growth is unlimited: - */ - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - } -} - /* * You really shouldn't be using read() or write() on /dev/mem. This might go * away in the future. diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 078950d9605b..00fcea236eba 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -264,7 +264,8 @@ extern struct ctl_table epoll_table[]; extern struct ctl_table firmware_config_table[]; #endif -#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT +#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ + defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) int sysctl_legacy_va_layout; #endif @@ -1573,7 +1574,8 @@ static struct ctl_table vm_table[] = { .proc_handler = proc_dointvec, .extra1 = SYSCTL_ZERO, }, -#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT +#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ + defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) { .procname = "legacy_va_layout", .data = &sysctl_legacy_va_layout, diff --git a/mm/util.c b/mm/util.c index 15a4fb0f5473..0781e5575cb3 100644 --- a/mm/util.c +++ b/mm/util.c @@ -17,7 +17,12 @@ #include #include #include +#include +#include #include +#include +#include +#include #include @@ -315,7 +320,78 @@ unsigned long randomize_stack_top(unsigned long stack_top) #endif } -#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) +#ifdef CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT +#ifdef CONFIG_ARCH_HAS_ELF_RANDOMIZE +unsigned long arch_mmap_rnd(void) +{ + unsigned long rnd; + +#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS + if (is_compat_task()) + rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); + else +#endif /* CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS */ + rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); + + return rnd << PAGE_SHIFT; +} +#endif /* CONFIG_ARCH_HAS_ELF_RANDOMIZE */ + +static int mmap_is_legacy(struct rlimit *rlim_stack) +{ + if (current->personality & ADDR_COMPAT_LAYOUT) + return 1; + + if (rlim_stack->rlim_cur == RLIM_INFINITY) + return 1; + + return sysctl_legacy_va_layout; +} + +/* + * Leave enough space between the mmap area and the stack to honour ulimit in + * the face of randomisation. + */ +#define MIN_GAP (SZ_128M) +#define MAX_GAP (STACK_TOP / 6 * 5) + +static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) +{ + unsigned long gap = rlim_stack->rlim_cur; + unsigned long pad = stack_guard_gap; + + /* Account for stack randomization if necessary */ + if (current->flags & PF_RANDOMIZE) + pad += (STACK_RND_MASK << PAGE_SHIFT); + + /* Values close to RLIM_INFINITY can overflow. */ + if (gap + pad > gap) + gap += pad; + + if (gap < MIN_GAP) + gap = MIN_GAP; + else if (gap > MAX_GAP) + gap = MAX_GAP; + + return PAGE_ALIGN(STACK_TOP - gap - rnd); +} + +void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) +{ + unsigned long random_factor = 0UL; + + if (current->flags & PF_RANDOMIZE) + random_factor = arch_mmap_rnd(); + + if (mmap_is_legacy(rlim_stack)) { + mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; + mm->get_unmapped_area = arch_get_unmapped_area; + } else { + mm->mmap_base = mmap_base(random_factor, rlim_stack); + mm->get_unmapped_area = arch_get_unmapped_area_topdown; + } +} +#elif defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) { mm->mmap_base = TASK_UNMAPPED_BASE; From patchwork Tue Jul 30 05:51:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11064987 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8272113A0 for ; Tue, 30 Jul 2019 05:57:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7283528704 for ; Tue, 30 Jul 2019 05:57:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5CA832871A; Tue, 30 Jul 2019 05:57:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F36B428704 for ; Tue, 30 Jul 2019 05:57:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726254AbfG3F5A (ORCPT ); Tue, 30 Jul 2019 01:57:00 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:46973 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3F5A (ORCPT ); Tue, 30 Jul 2019 01:57:00 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id ED0F7240009; Tue, 30 Jul 2019 05:56:51 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 05/14] arm64, mm: Make randomization selected by generic topdown mmap layout Date: Tue, 30 Jul 2019 01:51:04 -0400 Message-Id: <20190730055113.23635-6-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This commits selects ARCH_HAS_ELF_RANDOMIZE when an arch uses the generic topdown mmap layout functions so that this security feature is on by default. Note that this commit also removes the possibility for arm64 to have elf randomization and no MMU: without MMU, the security added by randomization is worth nothing. Signed-off-by: Alexandre Ghiti Acked-by: Catalin Marinas Acked-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain --- arch/Kconfig | 1 + arch/arm64/Kconfig | 1 - arch/arm64/kernel/process.c | 8 -------- mm/util.c | 11 +++++++++-- 4 files changed, 10 insertions(+), 11 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index a0bb6fa4d381..d4c1f0551dfe 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -705,6 +705,7 @@ config HAVE_ARCH_COMPAT_MMAP_BASES config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT bool depends on MMU + select ARCH_HAS_ELF_RANDOMIZE config HAVE_COPY_THREAD_TLS bool diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 14a194e63458..399f595ef852 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -16,7 +16,6 @@ config ARM64 select ARCH_HAS_DMA_MMAP_PGPROT select ARCH_HAS_DMA_PREP_COHERENT select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI - select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FAST_MULTIPLIER select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index f674f28df663..8ddc2471b054 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -548,14 +548,6 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ~0xf; } -unsigned long arch_randomize_brk(struct mm_struct *mm) -{ - if (is_compat_task()) - return randomize_page(mm->brk, SZ_32M); - else - return randomize_page(mm->brk, SZ_1G); -} - /* * Called from setup_new_exec() after (COMPAT_)SET_PERSONALITY. */ diff --git a/mm/util.c b/mm/util.c index 0781e5575cb3..16f1e56e2996 100644 --- a/mm/util.c +++ b/mm/util.c @@ -321,7 +321,15 @@ unsigned long randomize_stack_top(unsigned long stack_top) } #ifdef CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT -#ifdef CONFIG_ARCH_HAS_ELF_RANDOMIZE +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + /* Is the current task 32bit ? */ + if (!IS_ENABLED(CONFIG_64BIT) || is_compat_task()) + return randomize_page(mm->brk, SZ_32M); + + return randomize_page(mm->brk, SZ_1G); +} + unsigned long arch_mmap_rnd(void) { unsigned long rnd; @@ -335,7 +343,6 @@ unsigned long arch_mmap_rnd(void) return rnd << PAGE_SHIFT; } -#endif /* CONFIG_ARCH_HAS_ELF_RANDOMIZE */ static int mmap_is_legacy(struct rlimit *rlim_stack) { From patchwork Tue Jul 30 05:51:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11064997 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 04FBD13A4 for ; Tue, 30 Jul 2019 05:58:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EAEE628704 for ; Tue, 30 Jul 2019 05:58:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DEEF728716; Tue, 30 Jul 2019 05:58:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 95D6128704 for ; Tue, 30 Jul 2019 05:58:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726192AbfG3F6E (ORCPT ); Tue, 30 Jul 2019 01:58:04 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:35885 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3F6E (ORCPT ); Tue, 30 Jul 2019 01:58:04 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 4FBB7240007; Tue, 30 Jul 2019 05:57:58 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 06/14] arm: Properly account for stack randomization and stack guard gap Date: Tue, 30 Jul 2019 01:51:05 -0400 Message-Id: <20190730055113.23635-7-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This commit takes care of stack randomization and stack guard gap when computing mmap base address and checks if the task asked for randomization. This fixes the problem uncovered and not fixed for arm here: https://lkml.kernel.org/r/20170622200033.25714-1-riel@redhat.com Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Reviewed-by: Luis Chamberlain --- arch/arm/mm/mmap.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index f866870db749..bff3d00bda5b 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -18,8 +18,9 @@ (((pgoff)<> (PAGE_SHIFT - 12)) static int mmap_is_legacy(struct rlimit *rlim_stack) { @@ -35,6 +36,15 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) { unsigned long gap = rlim_stack->rlim_cur; + unsigned long pad = stack_guard_gap; + + /* Account for stack randomization if necessary */ + if (current->flags & PF_RANDOMIZE) + pad += (STACK_RND_MASK << PAGE_SHIFT); + + /* Values close to RLIM_INFINITY can overflow. */ + if (gap + pad > gap) + gap += pad; if (gap < MIN_GAP) gap = MIN_GAP; From patchwork Tue Jul 30 05:51:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065007 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B644313A0 for ; Tue, 30 Jul 2019 05:59:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A823F28704 for ; Tue, 30 Jul 2019 05:59:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9BE6828716; Tue, 30 Jul 2019 05:59:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5372B28704 for ; Tue, 30 Jul 2019 05:59:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726168AbfG3F7K (ORCPT ); Tue, 30 Jul 2019 01:59:10 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:50165 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3F7J (ORCPT ); Tue, 30 Jul 2019 01:59:09 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id E90EC240007; Tue, 30 Jul 2019 05:59:02 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 07/14] arm: Use STACK_TOP when computing mmap base address Date: Tue, 30 Jul 2019 01:51:06 -0400 Message-Id: <20190730055113.23635-8-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP mmap base address must be computed wrt stack top address, using TASK_SIZE is wrong since STACK_TOP and TASK_SIZE are not equivalent. Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Reviewed-by: Luis Chamberlain --- arch/arm/mm/mmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index bff3d00bda5b..0b94b674aa91 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -19,7 +19,7 @@ /* gap between mmap and stack */ #define MIN_GAP (128*1024*1024UL) -#define MAX_GAP ((TASK_SIZE)/6*5) +#define MAX_GAP ((STACK_TOP)/6*5) #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) static int mmap_is_legacy(struct rlimit *rlim_stack) @@ -51,7 +51,7 @@ static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) else if (gap > MAX_GAP) gap = MAX_GAP; - return PAGE_ALIGN(TASK_SIZE - gap - rnd); + return PAGE_ALIGN(STACK_TOP - gap - rnd); } /* From patchwork Tue Jul 30 05:51:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065019 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AC63113A0 for ; Tue, 30 Jul 2019 06:00:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9E3D928714 for ; Tue, 30 Jul 2019 06:00:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 91CEC2871A; Tue, 30 Jul 2019 06:00:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0AC0228714 for ; Tue, 30 Jul 2019 06:00:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726205AbfG3GAP (ORCPT ); Tue, 30 Jul 2019 02:00:15 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:51071 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3GAP (ORCPT ); Tue, 30 Jul 2019 02:00:15 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 558AF1BF211; Tue, 30 Jul 2019 06:00:08 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 08/14] arm: Use generic mmap top-down layout and brk randomization Date: Tue, 30 Jul 2019 01:51:07 -0400 Message-Id: <20190730055113.23635-9-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP arm uses a top-down mmap layout by default that exactly fits the generic functions, so get rid of arch specific code and use the generic version by selecting ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT. As ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT selects ARCH_HAS_ELF_RANDOMIZE, use the generic version of arch_randomize_brk since it also fits. Note that this commit also removes the possibility for arm to have elf randomization and no MMU: without MMU, the security added by randomization is worth nothing. Note that it is safe to remove STACK_RND_MASK since it matches the default value. Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Reviewed-by: Luis Chamberlain --- arch/arm/Kconfig | 2 +- arch/arm/include/asm/processor.h | 2 -- arch/arm/kernel/process.c | 5 --- arch/arm/mm/mmap.c | 62 -------------------------------- 4 files changed, 1 insertion(+), 70 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 33b00579beff..81b08b027e4e 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -7,7 +7,6 @@ config ARM select ARCH_HAS_BINFMT_FLAT select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEVMEM_IS_ALLOWED - select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_KEEPINITRD select ARCH_HAS_KCOV @@ -30,6 +29,7 @@ config ARM select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_IPC_PARSE_VERSION select BINFMT_FLAT_ARGVP_ENVP_ON_STACK select BUILDTIME_EXTABLE_SORT if MMU diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index 20c2f42454b8..614bf829e454 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -140,8 +140,6 @@ static inline void prefetchw(const void *ptr) #endif #endif -#define HAVE_ARCH_PICK_MMAP_LAYOUT - #endif #endif /* __ASM_ARM_PROCESSOR_H */ diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index f934a6739fc0..9485acc520a4 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -319,11 +319,6 @@ unsigned long get_wchan(struct task_struct *p) return 0; } -unsigned long arch_randomize_brk(struct mm_struct *mm) -{ - return randomize_page(mm->brk, 0x02000000); -} - #ifdef CONFIG_MMU #ifdef CONFIG_KUSER_HELPERS /* diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 0b94b674aa91..b8d912ac9e61 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -17,43 +17,6 @@ ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \ (((pgoff)<> (PAGE_SHIFT - 12)) - -static int mmap_is_legacy(struct rlimit *rlim_stack) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlim_stack->rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) -{ - unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = stack_guard_gap; - - /* Account for stack randomization if necessary */ - if (current->flags & PF_RANDOMIZE) - pad += (STACK_RND_MASK << PAGE_SHIFT); - - /* Values close to RLIM_INFINITY can overflow. */ - if (gap + pad > gap) - gap += pad; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(STACK_TOP - gap - rnd); -} - /* * We need to ensure that shared mappings are correctly aligned to * avoid aliasing issues with VIPT caches. We need to ensure that @@ -181,31 +144,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } -unsigned long arch_mmap_rnd(void) -{ - unsigned long rnd; - - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - - return rnd << PAGE_SHIFT; -} - -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) -{ - unsigned long random_factor = 0UL; - - if (current->flags & PF_RANDOMIZE) - random_factor = arch_mmap_rnd(); - - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - } -} - /* * You really shouldn't be using read() or write() on /dev/mem. This * might go away in the future. From patchwork Tue Jul 30 05:51:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065025 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3362D13A0 for ; Tue, 30 Jul 2019 06:01:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 237E928704 for ; Tue, 30 Jul 2019 06:01:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1379628725; Tue, 30 Jul 2019 06:01:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B78D828704 for ; Tue, 30 Jul 2019 06:01:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726133AbfG3GBT (ORCPT ); Tue, 30 Jul 2019 02:01:19 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:51183 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3GBT (ORCPT ); Tue, 30 Jul 2019 02:01:19 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 1E7431BF20D; Tue, 30 Jul 2019 06:01:12 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 09/14] mips: Properly account for stack randomization and stack guard gap Date: Tue, 30 Jul 2019 01:51:08 -0400 Message-Id: <20190730055113.23635-10-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This commit takes care of stack randomization and stack guard gap when computing mmap base address and checks if the task asked for randomization. This fixes the problem uncovered and not fixed for arm here: https://lkml.kernel.org/r/20170622200033.25714-1-riel@redhat.com Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Acked-by: Paul Burton Reviewed-by: Luis Chamberlain --- arch/mips/mm/mmap.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index d79f2b432318..f5c778113384 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -21,8 +21,9 @@ unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); /* gap between mmap and stack */ -#define MIN_GAP (128*1024*1024UL) -#define MAX_GAP ((TASK_SIZE)/6*5) +#define MIN_GAP (128*1024*1024UL) +#define MAX_GAP ((TASK_SIZE)/6*5) +#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) static int mmap_is_legacy(struct rlimit *rlim_stack) { @@ -38,6 +39,15 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) { unsigned long gap = rlim_stack->rlim_cur; + unsigned long pad = stack_guard_gap; + + /* Account for stack randomization if necessary */ + if (current->flags & PF_RANDOMIZE) + pad += (STACK_RND_MASK << PAGE_SHIFT); + + /* Values close to RLIM_INFINITY can overflow. */ + if (gap + pad > gap) + gap += pad; if (gap < MIN_GAP) gap = MIN_GAP; From patchwork Tue Jul 30 05:51:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065037 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CBE831399 for ; Tue, 30 Jul 2019 06:02:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BC30C28704 for ; Tue, 30 Jul 2019 06:02:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AD74928716; Tue, 30 Jul 2019 06:02:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 62E2728704 for ; Tue, 30 Jul 2019 06:02:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726165AbfG3GCX (ORCPT ); Tue, 30 Jul 2019 02:02:23 -0400 Received: from relay8-d.mail.gandi.net ([217.70.183.201]:38151 "EHLO relay8-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3GCX (ORCPT ); Tue, 30 Jul 2019 02:02:23 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 925B41BF20E; Tue, 30 Jul 2019 06:02:17 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 10/14] mips: Use STACK_TOP when computing mmap base address Date: Tue, 30 Jul 2019 01:51:09 -0400 Message-Id: <20190730055113.23635-11-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP mmap base address must be computed wrt stack top address, using TASK_SIZE is wrong since STACK_TOP and TASK_SIZE are not equivalent. Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Acked-by: Paul Burton Reviewed-by: Luis Chamberlain --- arch/mips/mm/mmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index f5c778113384..a7e84b2e71d7 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -22,7 +22,7 @@ EXPORT_SYMBOL(shm_align_mask); /* gap between mmap and stack */ #define MIN_GAP (128*1024*1024UL) -#define MAX_GAP ((TASK_SIZE)/6*5) +#define MAX_GAP ((STACK_TOP)/6*5) #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) static int mmap_is_legacy(struct rlimit *rlim_stack) @@ -54,7 +54,7 @@ static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) else if (gap > MAX_GAP) gap = MAX_GAP; - return PAGE_ALIGN(TASK_SIZE - gap - rnd); + return PAGE_ALIGN(STACK_TOP - gap - rnd); } #define COLOUR_ALIGN(addr, pgoff) \ From patchwork Tue Jul 30 05:51:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065047 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 88FCC1823 for ; Tue, 30 Jul 2019 06:03:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7531B28716 for ; Tue, 30 Jul 2019 06:03:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 66F3128725; Tue, 30 Jul 2019 06:03:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 39F8E28716 for ; Tue, 30 Jul 2019 06:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726232AbfG3GD2 (ORCPT ); Tue, 30 Jul 2019 02:03:28 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:46003 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3GD1 (ORCPT ); Tue, 30 Jul 2019 02:03:27 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 0BBC320006; Tue, 30 Jul 2019 06:03:21 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 11/14] mips: Adjust brk randomization offset to fit generic version Date: Tue, 30 Jul 2019 01:51:10 -0400 Message-Id: <20190730055113.23635-12-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This commit simply bumps up to 32MB and 1GB the random offset of brk, compared to 8MB and 256MB, for 32bit and 64bit respectively. Suggested-by: Kees Cook Signed-off-by: Alexandre Ghiti Acked-by: Paul Burton Reviewed-by: Kees Cook Reviewed-by: Luis Chamberlain --- arch/mips/mm/mmap.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index a7e84b2e71d7..ff6ab87e9c56 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -16,6 +16,7 @@ #include #include #include +#include unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); @@ -189,11 +190,11 @@ static inline unsigned long brk_rnd(void) unsigned long rnd = get_random_long(); rnd = rnd << PAGE_SHIFT; - /* 8MB for 32bit, 256MB for 64bit */ + /* 32MB for 32bit, 1GB for 64bit */ if (TASK_IS_32BIT_ADDR) - rnd = rnd & 0x7ffffful; + rnd = rnd & (SZ_32M - 1); else - rnd = rnd & 0xffffffful; + rnd = rnd & (SZ_1G - 1); return rnd; } From patchwork Tue Jul 30 05:51:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065057 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1F673746 for ; Tue, 30 Jul 2019 06:04:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0E12928704 for ; Tue, 30 Jul 2019 06:04:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F3DDC28716; Tue, 30 Jul 2019 06:04:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AA62128704 for ; Tue, 30 Jul 2019 06:04:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726168AbfG3GEd (ORCPT ); Tue, 30 Jul 2019 02:04:33 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:51251 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726033AbfG3GEd (ORCPT ); Tue, 30 Jul 2019 02:04:33 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 94A64E0005; Tue, 30 Jul 2019 06:04:26 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 12/14] mips: Replace arch specific way to determine 32bit task with generic version Date: Tue, 30 Jul 2019 01:51:11 -0400 Message-Id: <20190730055113.23635-13-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Mips uses TASK_IS_32BIT_ADDR to determine if a task is 32bit, but this define is mips specific and other arches do not have it: instead, use !IS_ENABLED(CONFIG_64BIT) || is_compat_task() condition. Signed-off-by: Alexandre Ghiti Acked-by: Paul Burton Reviewed-by: Kees Cook Reviewed-by: Luis Chamberlain --- arch/mips/mm/mmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index ff6ab87e9c56..d5106c26ac6a 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -17,6 +17,7 @@ #include #include #include +#include unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); @@ -191,7 +192,7 @@ static inline unsigned long brk_rnd(void) rnd = rnd << PAGE_SHIFT; /* 32MB for 32bit, 1GB for 64bit */ - if (TASK_IS_32BIT_ADDR) + if (!IS_ENABLED(CONFIG_64BIT) || is_compat_task()) rnd = rnd & (SZ_32M - 1); else rnd = rnd & (SZ_1G - 1); From patchwork Tue Jul 30 05:51:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065067 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C24E11399 for ; Tue, 30 Jul 2019 06:05:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B3B5A28517 for ; Tue, 30 Jul 2019 06:05:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A6FA02857E; Tue, 30 Jul 2019 06:05:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2FEC528517 for ; Tue, 30 Jul 2019 06:05:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726210AbfG3GFi (ORCPT ); Tue, 30 Jul 2019 02:05:38 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:47715 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725793AbfG3GFi (ORCPT ); Tue, 30 Jul 2019 02:05:38 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 148D9E0005; Tue, 30 Jul 2019 06:05:31 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 13/14] mips: Use generic mmap top-down layout and brk randomization Date: Tue, 30 Jul 2019 01:51:12 -0400 Message-Id: <20190730055113.23635-14-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP mips uses a top-down layout by default that exactly fits the generic functions, so get rid of arch specific code and use the generic version by selecting ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT. As ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT selects ARCH_HAS_ELF_RANDOMIZE, use the generic version of arch_randomize_brk since it also fits. Note that this commit also removes the possibility for mips to have elf randomization and no MMU: without MMU, the security added by randomization is worth nothing. Signed-off-by: Alexandre Ghiti Acked-by: Paul Burton Reviewed-by: Kees Cook Reviewed-by: Luis Chamberlain --- arch/mips/Kconfig | 2 +- arch/mips/include/asm/processor.h | 5 -- arch/mips/mm/mmap.c | 96 ------------------------------- 3 files changed, 1 insertion(+), 102 deletions(-) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index d50fafd7bf3a..4e85d7d2cf1a 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -5,7 +5,6 @@ config MIPS select ARCH_32BIT_OFF_T if !64BIT select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT select ARCH_CLOCKSOURCE_DATA - select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_SUPPORTS_UPROBES @@ -13,6 +12,7 @@ config MIPS select ARCH_USE_CMPXCHG_LOCKREF if 64BIT select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT select CLONE_BACKWARDS diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h index aca909bd7841..fba18d4a9190 100644 --- a/arch/mips/include/asm/processor.h +++ b/arch/mips/include/asm/processor.h @@ -29,11 +29,6 @@ extern unsigned int vced_count, vcei_count; -/* - * MIPS does have an arch_pick_mmap_layout() - */ -#define HAVE_ARCH_PICK_MMAP_LAYOUT 1 - #ifdef CONFIG_32BIT #ifdef CONFIG_KVM_GUEST /* User space process size is limited to 1GB in KVM Guest Mode */ diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index d5106c26ac6a..00fe90c6db3e 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -16,49 +16,10 @@ #include #include #include -#include -#include unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); -/* gap between mmap and stack */ -#define MIN_GAP (128*1024*1024UL) -#define MAX_GAP ((STACK_TOP)/6*5) -#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) - -static int mmap_is_legacy(struct rlimit *rlim_stack) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlim_stack->rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) -{ - unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = stack_guard_gap; - - /* Account for stack randomization if necessary */ - if (current->flags & PF_RANDOMIZE) - pad += (STACK_RND_MASK << PAGE_SHIFT); - - /* Values close to RLIM_INFINITY can overflow. */ - if (gap + pad > gap) - gap += pad; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(STACK_TOP - gap - rnd); -} - #define COLOUR_ALIGN(addr, pgoff) \ ((((addr) + shm_align_mask) & ~shm_align_mask) + \ (((pgoff) << PAGE_SHIFT) & shm_align_mask)) @@ -156,63 +117,6 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, addr0, len, pgoff, flags, DOWN); } -unsigned long arch_mmap_rnd(void) -{ - unsigned long rnd; - -#ifdef CONFIG_COMPAT - if (TASK_IS_32BIT_ADDR) - rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); - else -#endif /* CONFIG_COMPAT */ - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - - return rnd << PAGE_SHIFT; -} - -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) -{ - unsigned long random_factor = 0UL; - - if (current->flags & PF_RANDOMIZE) - random_factor = arch_mmap_rnd(); - - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - } -} - -static inline unsigned long brk_rnd(void) -{ - unsigned long rnd = get_random_long(); - - rnd = rnd << PAGE_SHIFT; - /* 32MB for 32bit, 1GB for 64bit */ - if (!IS_ENABLED(CONFIG_64BIT) || is_compat_task()) - rnd = rnd & (SZ_32M - 1); - else - rnd = rnd & (SZ_1G - 1); - - return rnd; -} - -unsigned long arch_randomize_brk(struct mm_struct *mm) -{ - unsigned long base = mm->brk; - unsigned long ret; - - ret = PAGE_ALIGN(base + brk_rnd()); - - if (ret < mm->brk) - return mm->brk; - - return ret; -} - bool __virt_addr_valid(const volatile void *kaddr) { unsigned long vaddr = (unsigned long)kaddr; From patchwork Tue Jul 30 05:51:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11065077 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6FAEA1399 for ; Tue, 30 Jul 2019 06:06:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 60F8628623 for ; Tue, 30 Jul 2019 06:06:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5547F28714; Tue, 30 Jul 2019 06:06:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C1C6928716 for ; Tue, 30 Jul 2019 06:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726281AbfG3GGn (ORCPT ); Tue, 30 Jul 2019 02:06:43 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:32931 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725793AbfG3GGn (ORCPT ); Tue, 30 Jul 2019 02:06:43 -0400 X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 9A460E0009; Tue, 30 Jul 2019 06:06:36 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Luis Chamberlain , Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v5 14/14] riscv: Make mmap allocation top-down by default Date: Tue, 30 Jul 2019 01:51:13 -0400 Message-Id: <20190730055113.23635-15-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190730055113.23635-1-alex@ghiti.fr> References: <20190730055113.23635-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In order to avoid wasting user address space by using bottom-up mmap allocation scheme, prefer top-down scheme when possible. Before: root@qemuriscv64:~# cat /proc/self/maps 00010000-00016000 r-xp 00000000 fe:00 6389 /bin/cat.coreutils 00016000-00017000 r--p 00005000 fe:00 6389 /bin/cat.coreutils 00017000-00018000 rw-p 00006000 fe:00 6389 /bin/cat.coreutils 00018000-00039000 rw-p 00000000 00:00 0 [heap] 1555556000-155556d000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so 155556d000-155556e000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so 155556e000-155556f000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so 155556f000-1555570000 rw-p 00000000 00:00 0 1555570000-1555572000 r-xp 00000000 00:00 0 [vdso] 1555574000-1555576000 rw-p 00000000 00:00 0 1555576000-1555674000 r-xp 00000000 fe:00 7187 /lib/libc-2.28.so 1555674000-1555678000 r--p 000fd000 fe:00 7187 /lib/libc-2.28.so 1555678000-155567a000 rw-p 00101000 fe:00 7187 /lib/libc-2.28.so 155567a000-15556a0000 rw-p 00000000 00:00 0 3fffb90000-3fffbb1000 rw-p 00000000 00:00 0 [stack] After: root@qemuriscv64:~# cat /proc/self/maps 00010000-00016000 r-xp 00000000 fe:00 6389 /bin/cat.coreutils 00016000-00017000 r--p 00005000 fe:00 6389 /bin/cat.coreutils 00017000-00018000 rw-p 00006000 fe:00 6389 /bin/cat.coreutils 2de81000-2dea2000 rw-p 00000000 00:00 0 [heap] 3ff7eb6000-3ff7ed8000 rw-p 00000000 00:00 0 3ff7ed8000-3ff7fd6000 r-xp 00000000 fe:00 7187 /lib/libc-2.28.so 3ff7fd6000-3ff7fda000 r--p 000fd000 fe:00 7187 /lib/libc-2.28.so 3ff7fda000-3ff7fdc000 rw-p 00101000 fe:00 7187 /lib/libc-2.28.so 3ff7fdc000-3ff7fe2000 rw-p 00000000 00:00 0 3ff7fe4000-3ff7fe6000 r-xp 00000000 00:00 0 [vdso] 3ff7fe6000-3ff7ffd000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so 3ff7ffd000-3ff7ffe000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so 3ff7ffe000-3ff7fff000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so 3ff7fff000-3ff8000000 rw-p 00000000 00:00 0 3fff888000-3fff8a9000 rw-p 00000000 00:00 0 [stack] Signed-off-by: Alexandre Ghiti Reviewed-by: Christoph Hellwig Reviewed-by: Kees Cook Reviewed-by: Luis Chamberlain Acked-by: Paul Walmsley # for arch/riscv --- arch/riscv/Kconfig | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 8ef64fe2c2b3..8d0d8af1a744 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -54,6 +54,19 @@ config RISCV select EDAC_SUPPORT select ARCH_HAS_GIGANTIC_PAGE select ARCH_WANT_HUGE_PMD_SHARE if 64BIT + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU + select HAVE_ARCH_MMAP_RND_BITS + +config ARCH_MMAP_RND_BITS_MIN + default 18 if 64BIT + default 8 + +# max bits determined by the following formula: +# VA_BITS - PAGE_SHIFT - 3 +config ARCH_MMAP_RND_BITS_MAX + default 33 if RISCV_VM_SV48 + default 24 if RISCV_VM_SV39 + default 17 if RISCV_VM_SV32 config MMU def_bool y