From patchwork Mon Dec 6 21:43:58 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: 12695006 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 E3B70C433F5 for ; Mon, 6 Dec 2021 22:00:14 +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=yt/maOHPvH56sKvOLcb13BVhHW59EUxCCZM56s7y4pw=; b=r91vju4I1tzO0J peo1LEzqTgXkR2drw81GHupaEBgg5eftfJmkNJRSzTMPvxLsYf79y1LZaWCBQG/uMtJiSEj+OWOfe Ld558tGty7JxkZCmWXZ/KZZlDqpwo3V3mvnn5gD2GT5ltrdkRROHYzNFgUR6QyY7CGbJjzStEJlEv CYHrgab1+F8D5HJrfpslFYtb+zrneoKXvIXi9ld+8t7JMuWkyj7gkTF42y63hxK2JUe9NSBplbB1K uzqu5aFRzAHqnc9GfdPqt2JWuGiSqGYyNk+KfVTh3dfhoIsjDaLecXwTqmGJRxz8qOSBCDKueHxGe 8zLjbqg7DtrkI1b4ULeA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1muM0F-0064Ss-8g; Mon, 06 Dec 2021 21:58:31 +0000 Received: from out2.migadu.com ([188.165.223.204]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1muLoH-005zJT-J2 for linux-arm-kernel@lists.infradead.org; Mon, 06 Dec 2021 21:46:11 +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=1638827168; 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=DG1z80n+FdxKIjaCouQa8EFEG7uKXNAbYhiqtcBDOzg=; b=vxro8/A3f6u+g9tCqrxJ0dPCIULo7w6FPsYXp/AX31m8If40/krW8khAxSScfLQhWgb8Eb YLQDToXJ/36hUhhZu/93oF+LNBqkmvSzLeIefrwDvKmBnQAgQXuP6tJXKAeV/VY01tLdfV PxQG8+Q+2QyGq/Fbt10fhQrtjPyL0ds= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH v2 21/34] kasan, vmalloc: reset tags in vmalloc functions Date: Mon, 6 Dec 2021 22:43:58 +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-20211206_134609_825221_4CDD4174 X-CRM114-Status: GOOD ( 12.51 ) 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 c5235e3e5857..a059b3100c0a 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(); @@ -3361,6 +3365,8 @@ 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;