From patchwork Wed Feb 16 13:13:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 12748521 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90E73C43217 for ; Wed, 16 Feb 2022 13:15:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233753AbiBPNQH (ORCPT ); Wed, 16 Feb 2022 08:16:07 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:60870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229796AbiBPNQG (ORCPT ); Wed, 16 Feb 2022 08:16:06 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31E6B2731E3; Wed, 16 Feb 2022 05:15:54 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BE57A6165A; Wed, 16 Feb 2022 13:15:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32B6BC004E1; Wed, 16 Feb 2022 13:15:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645017353; bh=dnkJIXtWvebNCasCXkRnJYZ7sRLI8mvE+toudMu0he4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mbkiU5PLLn4NDIE1XXLiEo1F9hdUdlYNtT43C6pnWMSMEnNcHeJT08TjKBv9wlavO TQIHyKwAX3Q9yO2QLTbU3OYm3uPc3/YkZ7pvQBmT2THInQo7TYroawkDZaAXL5vyhh FllPpmvpmlFK45kZzrO4qDSCsDu3EPqfKeJG9TFGZya4fxeNHv6Rte483uYLNxYD13 uQuYSntQKyv0TTj0RFsVxxEjWwl8zLgAtYDmfXlqvhM3RTaEiIW4u8rxBHtNMi1TA2 hi7WMFYafgmDnF458kFmL7tjX5qbqMQ6ZZzVXXp+YJKjhVUKCguz4UEfdreoEfaVtr MztkrmPVbc3qw== From: Arnd Bergmann To: Linus Torvalds , Christoph Hellwig , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, arnd@arndb.de, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Cc: linux@armlinux.org.uk, will@kernel.org, guoren@kernel.org, bcain@codeaurora.org, geert@linux-m68k.org, monstr@monstr.eu, tsbogend@alpha.franken.de, nickhu@andestech.com, green.hu@gmail.com, dinguyen@kernel.org, shorne@gmail.com, deller@gmx.de, mpe@ellerman.id.au, peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com, hca@linux.ibm.com, dalias@libc.org, davem@davemloft.net, richard@nod.at, x86@kernel.org, jcmvbkbc@gmail.com, ebiederm@xmission.com, akpm@linux-foundation.org, ardb@kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, stable@vger.kernel.org, David Laight Subject: [PATCH v2 01/18] uaccess: fix integer overflow on access_ok() Date: Wed, 16 Feb 2022 14:13:15 +0100 Message-Id: <20220216131332.1489939-2-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20220216131332.1489939-1-arnd@kernel.org> References: <20220216131332.1489939-1-arnd@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Arnd Bergmann Three architectures check the end of a user access against the address limit without taking a possible overflow into account. Passing a negative length or another overflow in here returns success when it should not. Use the most common correct implementation here, which optimizes for a constant 'size' argument, and turns the common case into a single comparison. Cc: stable@vger.kernel.org Fixes: da551281947c ("csky: User access") Fixes: f663b60f5215 ("microblaze: Fix uaccess_ok macro") Fixes: 7567746e1c0d ("Hexagon: Add user access functions") Reported-by: David Laight Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann --- arch/csky/include/asm/uaccess.h | 7 +++---- arch/hexagon/include/asm/uaccess.h | 18 +++++++++--------- arch/microblaze/include/asm/uaccess.h | 19 ++++--------------- 3 files changed, 16 insertions(+), 28 deletions(-) diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h index c40f06ee8d3e..ac5a54f57d40 100644 --- a/arch/csky/include/asm/uaccess.h +++ b/arch/csky/include/asm/uaccess.h @@ -3,14 +3,13 @@ #ifndef __ASM_CSKY_UACCESS_H #define __ASM_CSKY_UACCESS_H -#define user_addr_max() \ - (uaccess_kernel() ? KERNEL_DS.seg : get_fs().seg) +#define user_addr_max() (current_thread_info()->addr_limit.seg) static inline int __access_ok(unsigned long addr, unsigned long size) { - unsigned long limit = current_thread_info()->addr_limit.seg; + unsigned long limit = user_addr_max(); - return ((addr < limit) && ((addr + size) < limit)); + return (size <= limit) && (addr <= (limit - size)); } #define __access_ok __access_ok diff --git a/arch/hexagon/include/asm/uaccess.h b/arch/hexagon/include/asm/uaccess.h index ef5bfef8d490..719ba3f3c45c 100644 --- a/arch/hexagon/include/asm/uaccess.h +++ b/arch/hexagon/include/asm/uaccess.h @@ -25,17 +25,17 @@ * Returns true (nonzero) if the memory block *may* be valid, false (zero) * if it is definitely invalid. * - * User address space in Hexagon, like x86, goes to 0xbfffffff, so the - * simple MSB-based tests used by MIPS won't work. Some further - * optimization is probably possible here, but for now, keep it - * reasonably simple and not *too* slow. After all, we've got the - * MMU for backup. */ +#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) +#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE) -#define __access_ok(addr, size) \ - ((get_fs().seg == KERNEL_DS.seg) || \ - (((unsigned long)addr < get_fs().seg) && \ - (unsigned long)size < (get_fs().seg - (unsigned long)addr))) +static inline int __access_ok(unsigned long addr, unsigned long size) +{ + unsigned long limit = TASK_SIZE; + + return (size <= limit) && (addr <= (limit - size)); +} +#define __access_ok __access_ok /* * When a kernel-mode page fault is taken, the faulting instruction diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h index d2a8ef9f8978..5b6e0e7788f4 100644 --- a/arch/microblaze/include/asm/uaccess.h +++ b/arch/microblaze/include/asm/uaccess.h @@ -39,24 +39,13 @@ # define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) -static inline int access_ok(const void __user *addr, unsigned long size) +static inline int __access_ok(unsigned long addr, unsigned long size) { - if (!size) - goto ok; + unsigned long limit = user_addr_max(); - if ((get_fs().seg < ((unsigned long)addr)) || - (get_fs().seg < ((unsigned long)addr + size - 1))) { - pr_devel("ACCESS fail at 0x%08x (size 0x%x), seg 0x%08x\n", - (__force u32)addr, (u32)size, - (u32)get_fs().seg); - return 0; - } -ok: - pr_devel("ACCESS OK at 0x%08x (size 0x%x), seg 0x%08x\n", - (__force u32)addr, (u32)size, - (u32)get_fs().seg); - return 1; + return (size <= limit) && (addr <= (limit - size)); } +#define access_ok(addr, size) __access_ok((unsigned long)addr, size) # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"