From patchwork Thu Mar 23 17:25:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Garnier X-Patchwork-Id: 9641681 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 57257602CA for ; Thu, 23 Mar 2017 17:25:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 42F6225D99 for ; Thu, 23 Mar 2017 17:25:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 367DC2841E; Thu, 23 Mar 2017 17:25:50 +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 6409E2841C for ; Thu, 23 Mar 2017 17:25:49 +0000 (UTC) Received: (qmail 19512 invoked by uid 550); 23 Mar 2017 17:25:38 -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 18332 invoked from network); 23 Mar 2017 17:25:36 -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=jBcQfCvgcsLJjvtwLYJH8skdoKJL/5IprG1RrnK5JPQ=; b=POJRDSrB42KPoVlPb4Hk49oHaMcx4p82XDp+fQ+b6ZLUKUr7JFaAbCrBLeDuwFwK/U Q5Da78g/uvgZVc6stSq3mEjcS/sivjMIcBA2XcEFfO9HfGBSDDoAc/y9rpDOi0kjBDgO 3RQJ3fkb8lyfK6EHOPZwUKG0CWzDexKRyo1P5dbhUf1SN7zy5d6uYH4Q4jNtHN/iTCXd nfB2D+gqTQgPO79GURcT1wRo7RqrXCoqSK95A0IoJExV9qK5cjSMDc/XWBQK2Czn4jsB YDRpo9+lCJSyXNZWhCVQ5ElMkSognf7s1CJUha/Fp5nOyhZ6zx9qU1vIB6CdC3aGXwik BlfA== 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=jBcQfCvgcsLJjvtwLYJH8skdoKJL/5IprG1RrnK5JPQ=; b=R0KCq53gV1QP2fAe8+XIA6bZYZuzjbZsq64ZbngIMcg+Af0zbEiito3kY9IE7YZLWJ C0qHSSU3BecEv5vBdPoBSLoZoskCgbz9voRm2pt7UYL2WD+cI7eUgngzPcz+QdE5OdEd 6lqwU70KAmwyAstworXwFyQElaiYh+zhsioaylfdBDo/KCdY2jEQd7o7einh8/dwePq6 Jw9c9Xa293R9grd8P0EZaWcfB6uU0pDsM5LC4Xx6TLcgCdWnN0CzKxT42bCy9OS/eu9Z 7aRAhkEcyX6az6h4n6cT4cpZDgBY6V5N2vntCQ6k4s1spqihWoOl59LwbEnyfjFDmjji A6eQ== X-Gm-Message-State: AFeK/H2OJRre/fOTqJEjFWqQO/0IiHbjWA1gnz32DPJilHpbIZl66m/cLKFvOpQRkPR8buNY X-Received: by 10.98.155.28 with SMTP id r28mr4182701pfd.212.1490289925006; Thu, 23 Mar 2017 10:25:25 -0700 (PDT) From: Thomas Garnier To: Martin Schwidefsky , Heiko Carstens , David Howells , Arnd Bergmann , Dave Hansen , Al Viro , Thomas Gleixner , =?UTF-8?q?Ren=C3=A9=20Nyffenegger?= , Thomas Garnier , Andrew Morton , "Paul E . McKenney" , Ingo Molnar , Oleg Nesterov , Pavel Tikhomirov , Stephen Smalley , Ingo Molnar , "H . Peter Anvin" , Andy Lutomirski , Paolo Bonzini , Rik van Riel , Kees Cook , 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: Thu, 23 Mar 2017 10:25:14 -0700 Message-Id: <20170323172515.27950-3-thgarnie@google.com> X-Mailer: git-send-email 2.12.1.500.gab5fba24ee-goog In-Reply-To: <20170323172515.27950-1-thgarnie@google.com> References: <20170323172515.27950-1-thgarnie@google.com> Subject: [kernel-hardening] [PATCH v5 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-20170322 --- 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 fcbc5ef1ec69..10c6dc3dfff9 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 *-----------------------------------------------------------------------------