From patchwork Tue Apr 4 17:47:26 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Garnier X-Patchwork-Id: 9662277 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 14DF96032D for ; Tue, 4 Apr 2017 17:48:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0860E283A6 for ; Tue, 4 Apr 2017 17:48:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F0CB928520; Tue, 4 Apr 2017 17:48:06 +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=-4.1 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id E33AC283A6 for ; Tue, 4 Apr 2017 17:48:05 +0000 (UTC) Received: (qmail 13979 invoked by uid 550); 4 Apr 2017 17:47:52 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 13812 invoked from network); 4 Apr 2017 17:47:49 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=VJiuTWOmO1JqZjIphy1Kmldf1Ytte2PfX2FNI2PFK/4=; b=LLMkZ9WGGrTowjRY+OEzxmK+MmE63hvvuoBRTM4tI1wdKnb27/nPpZX80IWGH7jyKx lZgTzT7ho/DWISuWIn2Z3prL+a1H2c5jBU+NHDXBISaRjLoDZz+XdpYdRh7beDfqAD2t GRp27f8s7uheyf/1ADe15xlafvW5cX3Eof779KwRPSlZfpvvN+QovO4j2RNqcCYACPYV 0AoXc48QvlWs1WpkZfU2IDr1aQYdReX+2tlo0IA00/qp2hOpNrMcx9Vh9hYjopKjxGBF jxLPEakDpXMIYHAwuwbkCmpywmVwa7PzefceH+/piNHBJud1gOEjs4ReazE6G+0a1L0x ZOBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=VJiuTWOmO1JqZjIphy1Kmldf1Ytte2PfX2FNI2PFK/4=; b=Fki9tEF3jDiRtBR3dO+Av+HEkEynw0MxKC+mni3bkf2+sXNKV6+eK0tDjI7vI4iAkG H+imSzi7kDAlX6qAD4u4vie9u72jEwvkVbrHroxUA6ETGgpCDJUijhU8a3j4qO7kuBfy aR5FHIvUgJN4G/5zYykflygQnsfNPkvKHY8ddZDuwJzqyYRBxgNZrb858UCuphdDQssP ektEl0gSaRJyY5RwjxIaLi6kVgdW5xwyvJCLTvNB5JjUKny0dxxcEzMKBKweI88a1wog wgD7xPE5+5W95YNSCuc8t8I6YWWBcX0IGj4nRDBJccsw5BrhKGevVP58dQX6fDg4inG8 sjNQ== X-Gm-Message-State: AFeK/H2tdNWRlkWHQCcDgTt2DNR8Vrp8YZxLjBI41L8+dqbnSzez+oBT9nDfK6XLLVSJCBhG X-Received: by 10.84.211.130 with SMTP id c2mr30692750pli.82.1491328057797; Tue, 04 Apr 2017 10:47:37 -0700 (PDT) From: Thomas Garnier To: Martin Schwidefsky , Heiko Carstens , Dave Hansen , Arnd Bergmann , Thomas Gleixner , Al Viro , David Howells , Thomas Garnier , =?UTF-8?q?Ren=C3=A9=20Nyffenegger?= , Andrew Morton , "Paul E . McKenney" , Ingo Molnar , Oleg Nesterov , Stephen Smalley , Pavel Tikhomirov , Ingo Molnar , "H . Peter Anvin" , Andy Lutomirski , Paolo Bonzini , Kees Cook , Rik van Riel , Josh Poimboeuf , Borislav Petkov , Brian Gerst , "Kirill A . Shutemov" , Christian Borntraeger , Russell King , Will Deacon , Catalin Marinas , Mark Rutland , James Morse Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, kernel-hardening@lists.openwall.com Date: Tue, 4 Apr 2017 10:47:26 -0700 Message-Id: <20170404174727.35478-3-thgarnie@google.com> X-Mailer: git-send-email 2.12.2.715.g7642488e1d-goog In-Reply-To: <20170404174727.35478-1-thgarnie@google.com> References: <20170404174727.35478-1-thgarnie@google.com> Subject: [kernel-hardening] [PATCH v6 3/4] arm/syscalls: Specific usage of verify_pre_usermode_state X-Virus-Scanned: ClamAV using ClamSMTP Implement specific usage of verify_pre_usermode_state for user-mode returns for arm. Signed-off-by: Thomas Garnier --- Based on next-20170404 --- arch/arm/Kconfig | 1 + arch/arm/kernel/entry-common.S | 16 +++++++++++++++- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2cec306c7390..e2ebc7d37742 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -12,6 +12,7 @@ config ARM select ARCH_HAVE_CUSTOM_GPIO_H select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_MIGHT_HAVE_PC_PARPORT + select ARCH_NO_SYSCALL_VERIFY_PRE_USERMODE_STATE select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7 select ARCH_SUPPORTS_ATOMIC_RMW diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index eb5cd77bf1d8..88c72c4e44ad 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -12,6 +12,7 @@ #include #include #include +#include #ifdef CONFIG_AEABI #include #endif @@ -27,7 +28,6 @@ #include "entry-header.S" - .align 5 #if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING)) /* @@ -40,9 +40,12 @@ ret_fast_syscall: UNWIND(.fnstart ) UNWIND(.cantunwind ) disable_irq_notrace @ disable interrupts + ldr r2, [tsk, #TI_ADDR_LIMIT] ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK bne fast_work_pending + cmp r2, #TASK_SIZE + blne addr_limit_fail /* perform architecture specific actions before user return */ arch_ret_to_user r1, lr @@ -66,6 +69,7 @@ ret_fast_syscall: UNWIND(.cantunwind ) str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 disable_irq_notrace @ disable interrupts + ldr r2, [tsk, #TI_ADDR_LIMIT] ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK beq no_work_pending @@ -82,6 +86,7 @@ slow_work_pending: mov r2, why @ 'syscall' bl do_work_pending cmp r0, #0 + ldreq r2, [tsk, #TI_ADDR_LIMIT] beq no_work_pending movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE) ldmia sp, {r0 - r6} @ have to reload r0 - r6 @@ -99,9 +104,12 @@ ret_slow_syscall: disable_irq_notrace @ disable interrupts ENTRY(ret_to_user_from_irq) ldr r1, [tsk, #TI_FLAGS] + ldr r2, [tsk, #TI_ADDR_LIMIT] tst r1, #_TIF_WORK_MASK bne slow_work_pending no_work_pending: + cmp r2, #TASK_SIZE + blne addr_limit_fail asm_trace_hardirqs_on save = 0 /* perform architecture specific actions before user return */ @@ -125,6 +133,12 @@ ENTRY(ret_from_fork) b ret_slow_syscall ENDPROC(ret_from_fork) +addr_limit_fail: + stmfd sp!, {r0, lr} + bl asm_verify_pre_usermode_state + ldmfd sp!, {r0, lr} + ret lr + /*============================================================================= * SWI handler *-----------------------------------------------------------------------------