From patchwork Mon Jun 8 04:41:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11592507 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 89C13618 for ; Mon, 8 Jun 2020 04:41:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 56551206D5 for ; Mon, 8 Jun 2020 04:41:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rWC9Q3mX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 56551206D5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 460A76B0010; Mon, 8 Jun 2020 00:41:23 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 3E3BC6B000E; Mon, 8 Jun 2020 00:41:23 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 25AB96B0092; Mon, 8 Jun 2020 00:41:23 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0057.hostedemail.com [216.40.44.57]) by kanga.kvack.org (Postfix) with ESMTP id 060606B008A for ; Mon, 8 Jun 2020 00:41:23 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id C7FAF2F242 for ; Mon, 8 Jun 2020 04:41:22 +0000 (UTC) X-FDA: 76904795604.05.face32_180239226db7 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin05.hostedemail.com (Postfix) with ESMTP id AA773180E2F82 for ; Mon, 8 Jun 2020 04:41:22 +0000 (UTC) X-Spam-Summary: 2,0,0,103ecb0c0de47835,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1542:1711:1730:1747:1777:1792:2393:2525:2559:2563:2682:2685:2859:2895:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3865:3866:3867:3868:3870:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:6653:7576:9025:9545:9592:10004:11026:11257:11473:11658:11914:12043:12048:12295:12296:12297:12438:12517:12519:12555:12663:12679:12783:12986:14096:14181:14721:14849:21080:21451:21627:21939:21990:30003:30054:30070,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-62.2.0.100 64.100.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:1,LUA_SUMMARY:none X-HE-Tag: face32_180239226db7 X-Filterd-Recvd-Size: 3664 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Mon, 8 Jun 2020 04:41:22 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7DA9820760; Mon, 8 Jun 2020 04:41:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591591281; bh=1KFdmdnCR7RRQ1buMaFVxzQoATGArKFSUx/DO2jMC68=; h=Date:From:To:Subject:In-Reply-To:From; b=rWC9Q3mXg1/FgcqjOtL9sbTP5QxvlggqelW4nBNdbjH18PcanWVguSLGrGS4VEld2 p5MEM7NXdujKLFjqIrqRhu9tI0JNGwovYzoMr55iiAeg9oPyh6E/RRvTySiAYKzLZC k53N/4kszGH/DVJ5paukJAtdzw5ZhMAWJEbXWpRc= Date: Sun, 07 Jun 2020 21:41:21 -0700 From: Andrew Morton To: agordeev@linux.ibm.com, akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 24/54] mm/mmap.c: do not allow mappings outside of allowed limits Message-ID: <20200608044121.stuEeVRhM%akpm@linux-foundation.org> In-Reply-To: <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: AA773180E2F82 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Alexander Gordeev Subject: mm/mmap.c: do not allow mappings outside of allowed limits One can set a lowest possible address in /proc/sys/vm/mmap_min_addr and mmap below that bound nevertheless. It is possible to request a fixed mapping address below mmap_min_addr and succeed. This update adds early checks of mmap_min_addr and mmap_end boundaries and fixes the above issue. Apart from it is wrong I am not aware of any existing issue. Link: http://lkml.kernel.org/r/d6da1319114a331095052638f0ffa3ccb0be58f1.1584958099.git.agordeev@linux.ibm.com Signed-off-by: Alexander Gordeev Signed-off-by: Andrew Morton --- mm/mmap.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) --- a/mm/mmap.c~mm-mmapc-do-not-allow-mappings-outside-of-allowed-limits +++ a/mm/mmap.c @@ -62,6 +62,14 @@ #define arch_mmap_check(addr, len, flags) (0) #endif +#ifndef arch_get_mmap_end +#define arch_get_mmap_end(addr) (TASK_SIZE) +#endif + +#ifndef arch_get_mmap_base +#define arch_get_mmap_base(addr, base) (base) +#endif + #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS const int mmap_rnd_bits_min = CONFIG_ARCH_MMAP_RND_BITS_MIN; const int mmap_rnd_bits_max = CONFIG_ARCH_MMAP_RND_BITS_MAX; @@ -1369,6 +1377,7 @@ unsigned long do_mmap(struct file *file, unsigned long pgoff, unsigned long *populate, struct list_head *uf) { + const unsigned long mmap_end = arch_get_mmap_end(addr); struct mm_struct *mm = current->mm; int pkey = 0; @@ -1391,8 +1400,12 @@ unsigned long do_mmap(struct file *file, if (flags & MAP_FIXED_NOREPLACE) flags |= MAP_FIXED; - if (!(flags & MAP_FIXED)) + if (flags & MAP_FIXED) { + if ((addr < mmap_min_addr) || (addr > mmap_end)) + return -ENOMEM; + } else { addr = round_hint_to_min(addr); + } /* Careful about overflows.. */ len = PAGE_ALIGN(len); @@ -2074,14 +2087,6 @@ unsigned long vm_unmapped_area(struct vm return addr; } -#ifndef arch_get_mmap_end -#define arch_get_mmap_end(addr) (TASK_SIZE) -#endif - -#ifndef arch_get_mmap_base -#define arch_get_mmap_base(addr, base) (base) -#endif - /* Get an address range which is currently unmapped. * For shmat() with addr=0. *