From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: [PATCH v2 10/18] m68k: fix access_ok for coldfire Date: Wed, 16 Feb 2022 14:13:24 +0100 Message-ID: <20220216131332.1489939-11-arnd@kernel.org> References: <20220216131332.1489939-1-arnd@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=z0jy45CPcCnMWU49RuEWvQg0lS/kQhbe4GrVY3z8Tk0=; b=h278Z+SOXzXKGT vQq0MjRnl3o5NoquCb1smv52aDDGioSPK2UmYPMhqpyBmb1qRfAq4uZPeF6uDe/M1tm/MObG8Nadn +O8zDdj2BkZsz66866EBXUIUL/3XIG1/NVuDKQKhix9cXmrrkbKs2SjeLJJkOom6ycdHZ4bPMfW9a 66ulhPEnAYxPluot5SEFR6KDC8imjfr8mwrzJdCtGwsYg2QwKt57fJEs7bDA4b5XHTsMEiA0drmHG S1kSOoZLDFM79pHTLWK+IFLffKGZa5siei4xBmkb+FGprwKenjoiztOOj5gD54MSn4wif1qWRh3M8 cQXb4H6v/X4CTidg0YRA==; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645017443; bh=MxlH7OSdWg2oRBDys6vsaBDtcNFNrqae9GgCDj46MDk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sjI1N/Ysf6UohThwc+VXydeUqwNugfP8doF9H67EicATD6oaAkDsrCNS3AC/ubFNd ziBIxKGEAeyq4Bw3XdZgjBuNcKHeB1enctrHaLGU2ykGVgZHDsnbC5Wzwde0sZPsGo WD7WBQJHRS/PhCcVbk/s6TQX9q0zFJnPZsK3bgY0sTLsXoxe2RYo46AhoXLG6T8vLY ptfvBD5j0ki8uiIVLlwxNojr8S73bqQ6CnNgAESnFCyQrATHgA3qg0Clpwhp7O6ene UNjiTeS5j4av8zOGlm3gJWoU7z2Cw6gaTV6tNodGA/Zj7EYErzSRxKmSguUvyWCtWL X2GGlpG3o7PVg== In-Reply-To: <20220216131332.1489939-1-arnd@kernel.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane-mx.org@lists.infradead.org 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.k From: Arnd Bergmann While most m68k platforms use separate address spaces for user and kernel space, at least coldfire does not, and the other ones have a TASK_SIZE that is less than the entire 4GB address range. Using the default implementation of __access_ok() stops coldfire user space from trivially accessing kernel memory. Signed-off-by: Arnd Bergmann --- arch/m68k/include/asm/uaccess.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/m68k/include/asm/uaccess.h b/arch/m68k/include/asm/uaccess.h index 79617c0b2f91..8eb625e75452 100644 --- a/arch/m68k/include/asm/uaccess.h +++ b/arch/m68k/include/asm/uaccess.h @@ -12,14 +12,21 @@ #include /* We let the MMU do all checking */ -static inline int access_ok(const void __user *addr, +static inline int access_ok(const void __user *ptr, unsigned long size) { + unsigned long limit = TASK_SIZE; + unsigned long addr = (unsigned long)ptr; + /* * XXX: for !CONFIG_CPU_HAS_ADDRESS_SPACES this really needs to check * for TASK_SIZE! + * Removing this helper is probably sufficient. */ - return 1; + if (IS_ENABLED(CONFIG_CPU_HAS_ADDRESS_SPACES)) + return 1; + + return (size <= limit) && (addr <= (limit - size)); } /* -- 2.29.2