From patchwork Mon Dec 13 21:53:11 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: 12674673 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03261C433F5 for ; Mon, 13 Dec 2021 22:03:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2AE996B0098; Mon, 13 Dec 2021 16:54:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 25D026B0099; Mon, 13 Dec 2021 16:54:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 125B66B009A; Mon, 13 Dec 2021 16:54:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0243.hostedemail.com [216.40.44.243]) by kanga.kvack.org (Postfix) with ESMTP id 0385F6B0098 for ; Mon, 13 Dec 2021 16:54:15 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C013383E8F for ; Mon, 13 Dec 2021 21:54:04 +0000 (UTC) X-FDA: 78914124408.12.2EB3DDF Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by imf29.hostedemail.com (Postfix) with ESMTP id C97A212000D for ; Mon, 13 Dec 2021 21:54:02 +0000 (UTC) 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=1639432443; 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=td/TtoF7cXxMeVx908agEEKdFK6FpXlk5RKSWg4HTMg=; b=qtKtE2kmusrP8UhCICzGgfQ7wuB9SHDUGobGIXiPT0HT1ujU9JGrYFO0Xr4WUv+oVcF16r bIuF+IG0xlHSg6THx9BFdsoU719C1vKuNQ/2BilR3FCuWIrQOqUpF7HNicqq6YOB4Alu+3 EFc9/vHa1I0io8eZmTh57ykDgGZHjBs= 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 v3 21/38] kasan, vmalloc: reset tags in vmalloc functions Date: Mon, 13 Dec 2021 22:53:11 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: andrey.konovalov@linux.dev X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: C97A212000D X-Stat-Signature: brzux1qos6ztbd1wjb8gjb6zhq5poehd Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=qtKtE2km; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf29.hostedemail.com: domain of andrey.konovalov@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev X-HE-Tag: 1639432442-555653 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: 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 a6b61e24a703..42406c53e2a5 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -72,7 +72,7 @@ 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; } @@ -630,7 +630,7 @@ 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 @@ -804,6 +804,8 @@ 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; @@ -825,6 +827,8 @@ 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; @@ -2143,7 +2147,7 @@ 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(); @@ -3394,6 +3398,8 @@ 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;