From patchwork Tue Jul 23 17:58:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 11054905 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 31125746 for ; Tue, 23 Jul 2019 17:59:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1F4AB286C8 for ; Tue, 23 Jul 2019 17:59:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1291D286F3; Tue, 23 Jul 2019 17:59:54 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 945D0286C8 for ; Tue, 23 Jul 2019 17:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:To:From:Subject:References:Mime-Version :Message-Id:In-Reply-To:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ouIUGUhXfNeFV7uhmI9L02uY+xhcQpfq5Ifo0aqjchs=; b=escxmhzbY+UiHp c/DnOBpgJIdDdoZIQZU/dDCLcdcJSwYW6+8K1HQZ7Luh4XK9r5IGEsyd20ZNkin7O4YzykU/rBVSm NOsgPKsWeq7Q/Ns9ZDXL8YDiwH1PwPpGniAH+oEJWfQ+6bWI/zcnk16oTiKaoF2TBD6Lms32FauP0 lIuj43V1FzN6VViJ/GMeivs5O6Fh3lDV0c67Ot72tFK0heYs3iDWy3IGeaSrSjo1RgrARmKH94VGj 6irM9FefO/HVleoXNbHxvsWLjLZtshK82pYyrLh9I6PVUgHqx07rrRq4rLq07g7wFEz6XAKYa/lgX zkk6zaE2MIcPibLOlhyw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hpz4q-0005sH-3i; Tue, 23 Jul 2019 17:59:52 +0000 Received: from mail-yb1-xb49.google.com ([2607:f8b0:4864:20::b49]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hpz4B-0005EU-NV for linux-arm-kernel@lists.infradead.org; Tue, 23 Jul 2019 17:59:13 +0000 Received: by mail-yb1-xb49.google.com with SMTP id f126so33620697ybg.16 for ; Tue, 23 Jul 2019 10:59:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=uxuxpoqA/C7rk06bc2rM9al5Hb55km4kp2za7lpV0D8=; b=gvBkOkwzaYNLh+oGcJAVB7MjFm6ggJ16J7ZtFWSs5smrgxbyTgnFANakPKwfHBaKJo Z3AeBj5hFUm+GIYoHcLDXyEq448i3WGfVM80s/ZYt3Ff7Lnffb2whFy1iyiq0vNB8tme ZgEAhcj6PmMNwScnzwOlSrD9vrs9BWD5XfY+Jc7tfz6fIGBdIIOc361XhF1FnJ2J5gIc R3XqyRsgPc72AURET11IAyvFYp4TC8kAAhKarnjk3baGMHuxZXMV89tXjZO+C8I9PfEc YEGyFP+vd3pK7Yts8v+bEOrkzxv2fC0rSmwv0ECVx3Gypru+tBZwBnoAh4W0hQ7k4cn/ 8ScQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=uxuxpoqA/C7rk06bc2rM9al5Hb55km4kp2za7lpV0D8=; b=SbyqpWwvfR/cisU5DVfh/f0FVoATm/d05I0N4TqN8rliPbnLN0Rjvsv6dN8vLTfxrg lnjeanKzgq6MN2W3D7XdSByxpsDtKqDLkVtgbnFLvCeumgq2BP6HvPj44Uk0U54ztW+G XY72BSGxEULzwLrngsoznqxIkX3DsqV2hVe9V106+OCLXMxK9A3hG4uO8qo8gaas5d37 1i+hKG0BQ4HG3/g43I1ktAl3cyGJNjhM2auWtCcoJSF6kSpUsFkRpTVX4GThwdQxc0Cb VLgQILg0wtbr5upM1hELbVzgrDRUYNIq12H5BB6RbjHkrw090aGTTHhV2WgC3Ii+eiI1 IfJw== X-Gm-Message-State: APjAAAULZ/k+G+FGp0rEpI2GnPOgMF1nymni0cLbgT33UAdsldf6zeAX wEsP8K7eWItb+/3iGrH5h+iXE191E+99uK2Zupm1iKhrL+GsaUbN0OecP59vcO2TMfJi4TwJKjC KZvLJrjLJlExb6Hh0x8MrsU8kxPJic36A1RcsiF67z6VZ/T5M9n49yu5kHt/LKbCtfeMT6TNFYu zLWex5G3h+mmqCvco= X-Google-Smtp-Source: APXvYqw9DwaHVI19t/YbteMrcIZMKltNbSnI88dDsWcfp8XIUhxn9zscDjBOZxYqaezV+ZapgNfd0Az5q5SxMU+h X-Received: by 2002:a5b:951:: with SMTP id x17mr48178059ybq.511.1563904749116; Tue, 23 Jul 2019 10:59:09 -0700 (PDT) Date: Tue, 23 Jul 2019 19:58:38 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.709.g102302147b-goog Subject: [PATCH v19 01/15] arm64: untag user pointers in access_ok and __uaccess_mask_ptr From: Andrey Konovalov To: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190723_105911_924388_D13DA431 X-CRM114-Status: GOOD ( 14.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Szabolcs Nagy , Catalin Marinas , Will Deacon , Kostya Serebryany , Khalid Aziz , Felix Kuehling , Vincenzo Frascino , Jacob Bramley , Leon Romanovsky , Christoph Hellwig , Jason Gunthorpe , Dave Martin , Evgeniy Stepanov , Kevin Brodsky , Kees Cook , Ruben Ayrapetyan , Andrey Konovalov , Ramana Radhakrishnan , Alex Williamson , Mauro Carvalho Chehab , Dmitry Vyukov , Greg Kroah-Hartman , Yishai Hadas , Jens Wiklander , Lee Smith , Alexander Deucher , Andrew Morton , enh , Robin Murphy , Christian Koenig , Luc Van Oostenryck Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. copy_from_user (and a few other similar functions) are used to copy data from user memory into the kernel memory or vice versa. Since a user can provided a tagged pointer to one of the syscalls that use copy_from_user, we need to correctly handle such pointers. Do this by untagging user pointers in access_ok and in __uaccess_mask_ptr, before performing access validity checks. Note, that this patch only temporarily untags the pointers to perform the checks, but then passes them as is into the kernel internals. Reviewed-by: Vincenzo Frascino Reviewed-by: Kees Cook Reviewed-by: Catalin Marinas Signed-off-by: Andrey Konovalov --- arch/arm64/include/asm/uaccess.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 5a1c32260c1f..a138e3b4f717 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -62,6 +62,8 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si { unsigned long ret, limit = current_thread_info()->addr_limit; + addr = untagged_addr(addr); + __chk_user_ptr(addr); asm volatile( // A + B <= C + 1 for all A,B,C, in four easy steps: @@ -215,7 +217,8 @@ static inline void uaccess_enable_not_uao(void) /* * Sanitise a uaccess pointer such that it becomes NULL if above the - * current addr_limit. + * current addr_limit. In case the pointer is tagged (has the top byte set), + * untag the pointer before checking. */ #define uaccess_mask_ptr(ptr) (__typeof__(ptr))__uaccess_mask_ptr(ptr) static inline void __user *__uaccess_mask_ptr(const void __user *ptr) @@ -223,10 +226,11 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) void __user *safe_ptr; asm volatile( - " bics xzr, %1, %2\n" + " bics xzr, %3, %2\n" " csel %0, %1, xzr, eq\n" : "=&r" (safe_ptr) - : "r" (ptr), "r" (current_thread_info()->addr_limit) + : "r" (ptr), "r" (current_thread_info()->addr_limit), + "r" (untagged_addr(ptr)) : "cc"); csdb();