From patchwork Mon Mar 18 17:17:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10858219 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 D1AC214DE for ; Mon, 18 Mar 2019 17:19:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8BEBB26E3C for ; Mon, 18 Mar 2019 17:19:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7D80528066; Mon, 18 Mar 2019 17:19:06 +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=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EAF762936B for ; Mon, 18 Mar 2019 17:19:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727752AbfCRRTF (ORCPT ); Mon, 18 Mar 2019 13:19:05 -0400 Received: from mail-qk1-f202.google.com ([209.85.222.202]:37084 "EHLO mail-qk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727971AbfCRRSS (ORCPT ); Mon, 18 Mar 2019 13:18:18 -0400 Received: by mail-qk1-f202.google.com with SMTP id r9so15350677qkl.4 for ; Mon, 18 Mar 2019 10:18:17 -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=MbZWy7wAoKF2UH6KYiAHojRGCKZALRbT18PDS+70hHM=; b=dTJdgx9rsdhWwnH1vj3NCjwrEhJg/K0jCXzsmKz7jGqUZPjqwUKpFn+JEqgSqgARw9 GrzD9yyxUHnRskQDw06ApmJmm4CviNLtYfaeZvHjLd+qEW/xvKmpZ5tctndli+aq+QJ+ mN64ZM999i8sOV7xSisbUkRr7FtVDWyYxMIQoLM+kZd6b4bIMr962tyM0XVMA+4Q18Qd lVla1m0kLDsWhi4cKBVmQI6ReqbQA7JBzC8qCDo47JiKKxjfiE4rs0YovHR0owNKBMBX ZJCYPGfxLUSYTCbfgcVQ0olftrEme4tvTFhAZs+XoCLg9KByJFWUuoPw+gnbDN8qzSKS I9pQ== 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=MbZWy7wAoKF2UH6KYiAHojRGCKZALRbT18PDS+70hHM=; b=XBQNydFAOXLR4z6OQWq/OUR5Qx/IC6pgS9AImLz17pys2+8uiJNC7D2BugqHEP45Ha qju+1beA7418G8w1r1PspMr0B0VVTI+Ar1ZOEeR8ja3eEHyVaw9xuIfXar1bwVKjZJVG JU6c5B7nRgxrGnuIjDUqIJIjiN0QiqyZ2SFy3fgc+ZjEEKWkdCNj17e+N0sfJ7Q1kO04 fUxMO/PbyXHi0Wh/ULVZRSXKiL3jgdcL/DRya/qom4YgEoLh9bPW1IQZUCXlth9uom3p 8a0QJv/DXhbqOsgVdTiXRl645vYiiGrBInuJRWfDu4vjaj5UDcXxYhR1agwFdbdf+Fb2 evFQ== X-Gm-Message-State: APjAAAUeIyGXRp7s7UNbKOdpU2JC4as6N/SMLEKLMzXsvvrB0eJuKdFQ LeHTGCd6/x2ooHATds5meXJpAWkqbt08CiPl X-Google-Smtp-Source: APXvYqyzI2O9PCu/G52HAhDudo47fXjMCsiQUjfmsAvF2tFQ9HZJ/l6jqHwwYscpkKbnsmeTP6mnJBPbZYdiBoYi X-Received: by 2002:ac8:821:: with SMTP id u30mr9205117qth.12.1552929496933; Mon, 18 Mar 2019 10:18:16 -0700 (PDT) Date: Mon, 18 Mar 2019 18:17:41 +0100 In-Reply-To: Message-Id: <82bc7a289c6b9162c64a25b1e6f60f0318db779b.1552929301.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.225.g810b269d1ac-goog Subject: [PATCH v12 09/13] kernel, arm64: untag user pointers in prctl_set_mm* From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , Vincenzo Frascino , Eric Dumazet , "David S. Miller" , Alexei Starovoitov , Daniel Borkmann , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is a part of a series that extends arm64 kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. prctl_set_mm() and prctl_set_mm_map() use provided user pointers for vma lookups and do some pointer comparisons to perform validation, which can only by done with untagged pointers. Untag user pointers in these functions for vma lookup and validity checks. Signed-off-by: Andrey Konovalov --- kernel/sys.c | 44 ++++++++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 14 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index 12df0e5434b8..fe26ccf3c9e6 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1885,11 +1885,12 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) * WARNING: we don't require any capability here so be very careful * in what is allowed for modification from userspace. */ -static int validate_prctl_map(struct prctl_mm_map *prctl_map) +static int validate_prctl_map(struct prctl_mm_map *tagged_prctl_map) { unsigned long mmap_max_addr = TASK_SIZE; struct mm_struct *mm = current->mm; int error = -EINVAL, i; + struct prctl_mm_map prctl_map; static const unsigned char offsets[] = { offsetof(struct prctl_mm_map, start_code), @@ -1905,12 +1906,25 @@ static int validate_prctl_map(struct prctl_mm_map *prctl_map) offsetof(struct prctl_mm_map, env_end), }; + memcpy(&prctl_map, tagged_prctl_map, sizeof(prctl_map)); + prctl_map.start_code = untagged_addr(prctl_map.start_code); + prctl_map.end_code = untagged_addr(prctl_map.end_code); + prctl_map.start_data = untagged_addr(prctl_map.start_data); + prctl_map.end_data = untagged_addr(prctl_map.end_data); + prctl_map.start_brk = untagged_addr(prctl_map.start_brk); + prctl_map.brk = untagged_addr(prctl_map.brk); + prctl_map.start_stack = untagged_addr(prctl_map.start_stack); + prctl_map.arg_start = untagged_addr(prctl_map.arg_start); + prctl_map.arg_end = untagged_addr(prctl_map.arg_end); + prctl_map.env_start = untagged_addr(prctl_map.env_start); + prctl_map.env_end = untagged_addr(prctl_map.env_end); + /* * Make sure the members are not somewhere outside * of allowed address space. */ for (i = 0; i < ARRAY_SIZE(offsets); i++) { - u64 val = *(u64 *)((char *)prctl_map + offsets[i]); + u64 val = *(u64 *)((char *)&prctl_map + offsets[i]); if ((unsigned long)val >= mmap_max_addr || (unsigned long)val < mmap_min_addr) @@ -1921,8 +1935,8 @@ static int validate_prctl_map(struct prctl_mm_map *prctl_map) * Make sure the pairs are ordered. */ #define __prctl_check_order(__m1, __op, __m2) \ - ((unsigned long)prctl_map->__m1 __op \ - (unsigned long)prctl_map->__m2) ? 0 : -EINVAL + ((unsigned long)prctl_map.__m1 __op \ + (unsigned long)prctl_map.__m2) ? 0 : -EINVAL error = __prctl_check_order(start_code, <, end_code); error |= __prctl_check_order(start_data, <, end_data); error |= __prctl_check_order(start_brk, <=, brk); @@ -1937,23 +1951,24 @@ static int validate_prctl_map(struct prctl_mm_map *prctl_map) /* * @brk should be after @end_data in traditional maps. */ - if (prctl_map->start_brk <= prctl_map->end_data || - prctl_map->brk <= prctl_map->end_data) + if (prctl_map.start_brk <= prctl_map.end_data || + prctl_map.brk <= prctl_map.end_data) goto out; /* * Neither we should allow to override limits if they set. */ - if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, - prctl_map->start_brk, prctl_map->end_data, - prctl_map->start_data)) + if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map.brk, + prctl_map.start_brk, prctl_map.end_data, + prctl_map.start_data)) goto out; /* * Someone is trying to cheat the auxv vector. */ - if (prctl_map->auxv_size) { - if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv)) + if (prctl_map.auxv_size) { + if (!prctl_map.auxv || prctl_map.auxv_size > + sizeof(mm->saved_auxv)) goto out; } @@ -1962,7 +1977,7 @@ static int validate_prctl_map(struct prctl_mm_map *prctl_map) * change /proc/pid/exe link: only local sys admin should * be allowed to. */ - if (prctl_map->exe_fd != (u32)-1) { + if (prctl_map.exe_fd != (u32)-1) { if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN)) goto out; } @@ -2120,13 +2135,14 @@ static int prctl_set_mm(int opt, unsigned long addr, if (opt == PR_SET_MM_AUXV) return prctl_set_auxv(mm, addr, arg4); - if (addr >= TASK_SIZE || addr < mmap_min_addr) + if (untagged_addr(addr) >= TASK_SIZE || + untagged_addr(addr) < mmap_min_addr) return -EINVAL; error = -EINVAL; down_write(&mm->mmap_sem); - vma = find_vma(mm, addr); + vma = find_vma(mm, untagged_addr(addr)); prctl_map.start_code = mm->start_code; prctl_map.end_code = mm->end_code;