From patchwork Mon Dec 20 21:59:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12696926 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D5EEEC433EF for ; Mon, 20 Dec 2021 22:13:12 +0000 (UTC) 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=f58BfgpjnDdYvoEDESk5QMsyOYbtOVvmeUT2ZJ89gzI=; b=hpdPXv8OtIHePU DUhThvfE+Q29XBCAbAmA+yNsMRhWNpL8VIlPjMbxtd7V0TSZmrb7Qyloic4DTjkn5BKtak1sv9h71 TdIpQOS+sHe22YJmAwEA9sv5s34S5LwisSHM0BCzmRGI3i6Gb6asvZr8IRg4cRlcJCTts0Z+iqyKA BAxsuD5ZiB5kdEGd3YXkU/6XgUpQCU2yeCNLr0UGcKMHaZALwC2vOnXpfH5l5ryNtLXUyBrfTwq1I knywZfybY68h90MYz8V5ZcnOA4e0u/n0ibIyOfCaUNkkDOZQT4m6sMTs545sG0Sg2NzQqABHUR9jk LaPzUaCnzqhb4UmZwExw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mzQsr-004hi0-7S; Mon, 20 Dec 2021 22:11:53 +0000 Received: from out1.migadu.com ([2001:41d0:2:863f::]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mzQhn-004bW0-8Y for linux-arm-kernel@lists.infradead.org; Mon, 20 Dec 2021 22:00:28 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1640037625; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZYMkDyTA14TCHWK1+gvITVpmr4ZV7O4DHhp5KoEByVw=; b=TA4mQFnrtqV6PiB0sDy104rgupwRkB63dwG8lXTQVEhksWCixie9CZP2WILPS6N4pUHl+l ynKIW5NzkQsZwGeAWh7rLoxruINlH3iwb+QolawAW56uRSUcKzRDpKCXe3T2OK7FWgnPfa Mq+d0m2gHLxVcfBpvikL/C6lMpbumbg= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Andrew Morton Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, linux-mm@kvack.org, Vincenzo Frascino , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Peter Collingbourne , Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm v4 21/39] kasan, vmalloc: reset tags in vmalloc functions Date: Mon, 20 Dec 2021 22:59:36 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211220_140027_518478_560C6494 X-CRM114-Status: GOOD ( 12.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Andrey Konovalov In preparation for adding vmalloc support to SW/HW_TAGS KASAN, reset pointer tags in functions that use pointer values in range checks. vread() is a special case here. Despite the untagging of the addr pointer in its prologue, the accesses performed by vread() are checked. Instead of accessing the virtual mappings though addr directly, vread() recovers the physical address via page_address(vmalloc_to_page()) and acceses that. And as page_address() recovers the pointer tag, the accesses get checked. Signed-off-by: Andrey Konovalov --- Changes v1->v2: - Clarified the description of untagging in vread(). --- mm/vmalloc.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 10011a07231d..eaacdf3abfa7 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -73,7 +73,7 @@ static const bool vmap_allow_huge = false; bool is_vmalloc_addr(const void *x) { - unsigned long addr = (unsigned long)x; + unsigned long addr = (unsigned long)kasan_reset_tag(x); return addr >= VMALLOC_START && addr < VMALLOC_END; } @@ -631,7 +631,7 @@ int is_vmalloc_or_module_addr(const void *x) * just put it in the vmalloc space. */ #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) - unsigned long addr = (unsigned long)x; + unsigned long addr = (unsigned long)kasan_reset_tag(x); if (addr >= MODULES_VADDR && addr < MODULES_END) return 1; #endif @@ -805,6 +805,8 @@ static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr) struct vmap_area *va = NULL; struct rb_node *n = vmap_area_root.rb_node; + addr = (unsigned long)kasan_reset_tag((void *)addr); + while (n) { struct vmap_area *tmp; @@ -826,6 +828,8 @@ static struct vmap_area *__find_vmap_area(unsigned long addr) { struct rb_node *n = vmap_area_root.rb_node; + addr = (unsigned long)kasan_reset_tag((void *)addr); + while (n) { struct vmap_area *va; @@ -2144,7 +2148,7 @@ EXPORT_SYMBOL_GPL(vm_unmap_aliases); void vm_unmap_ram(const void *mem, unsigned int count) { unsigned long size = (unsigned long)count << PAGE_SHIFT; - unsigned long addr = (unsigned long)mem; + unsigned long addr = (unsigned long)kasan_reset_tag(mem); struct vmap_area *va; might_sleep(); @@ -3406,6 +3410,8 @@ long vread(char *buf, char *addr, unsigned long count) unsigned long buflen = count; unsigned long n; + addr = kasan_reset_tag(addr); + /* Don't allow overflow */ if ((unsigned long) addr + count < count) count = -(unsigned long) addr;