From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9728C433E1 for ; Fri, 31 Jul 2020 13:20:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 910B82245C for ; Fri, 31 Jul 2020 13:20:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="jrdVI+Gq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732274AbgGaNUy (ORCPT ); Fri, 31 Jul 2020 09:20:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730237AbgGaNUw (ORCPT ); Fri, 31 Jul 2020 09:20:52 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A864FC061574 for ; Fri, 31 Jul 2020 06:20:52 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id n12so2993050qtr.6 for ; Fri, 31 Jul 2020 06:20:52 -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=RlSgKw0WaVPNPMJUtAR6IXtLReCVIjzNVv/S08XnLBI=; b=jrdVI+GqTxgA9hZqHbzpLWJLWfVIE9QekpGjHxYrEudEbxBY7QMNQrgeCpkUg5LkmQ eXTMUrrM/5o50zNnRTiTMrEbgBSzCPrS+pMt/VzDAYlQ5hCUWMO4rgrgTe9wTc9WzDjt yVVaBUGXvIkH2mXii1LTq5R7Uno85gLoAhxVhC0T9khb6ZyC/CxiqVjGFL0kCEJgWM9b YqUEgf3dPV+PFSiKBBVpNk3lA3vpAYlRBxZpzz0zqeFggEJfIlNh+f3r1HdJSfCwgC1C +2N6ukc3ohBjlfozUpubiwL1aaF1S5iNGuYk5jU44+NmYGYsEJ5/Q6eFNYxKJvg0pa5b VV0Q== 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=RlSgKw0WaVPNPMJUtAR6IXtLReCVIjzNVv/S08XnLBI=; b=qGzw8762BY1udklAy6KRb2EbalZlgb0zkta7RpB/B+4lwhuADGxsTIgXXC+dcXghwm oszLkg1pkcpfvOGNI0SaZeH3Bly+vTXldP3+fAszXfoya8jN4NtYCO+FIwlrlEOl5qfC 4pUZeYLBlZPrb42G732PRr4iIaIdyd3vEI1kl8iyEJosY8H9gWzQ1JPhXbbPSsjec6oQ MBxK3tYKvh3opayhFRJxuPJmUcb5m0YQTsyogI0jLwom4A6h/5aqrIydSxu4v7aQ3HJI CYllkIIoLzFJNDUzJAu5VzKoxq6G7EqecdvyljzIIozWtdiRAhF14EBDHCVXoOvlL9m1 ZjyQ== X-Gm-Message-State: AOAM533Bz4RTIElzfBxDAf6wW5+8HTG+T3scKXZfhQgBB+H5yEyaFc6h IfZyyHsLTdfFyhKseiNxH7A5jLLGzV0mc6Ye X-Google-Smtp-Source: ABdhPJx3HXBXn8SZsqgIUbyWhyba7Bd+WiRjFmLNSp8HElgnnStw91f4GBcwMeRt6NhnDO1hVA2GYUm2iS/Zt/i0 X-Received: by 2002:a0c:aac8:: with SMTP id g8mr4079969qvb.70.1596201651864; Fri, 31 Jul 2020 06:20:51 -0700 (PDT) Date: Fri, 31 Jul 2020 15:20:38 +0200 In-Reply-To: Message-Id: <01c678b877755bcf29009176592402cdf6f2cb15.1596199677.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.28.0.163.g6104cc2f0b6-goog Subject: [PATCH 1/4] kasan: don't tag stacks allocated with pagealloc From: Andrey Konovalov To: Andrew Morton Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Marco Elver , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Walter Wu , Elena Petrova , Vincenzo Frascino , Catalin Marinas , Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch prepares Software Tag-Based KASAN for stack tagging support. With Tag-Based KASAN when kernel stacks are allocated via pagealloc (which happens when CONFIG_VMAP_STACK is not enabled), they get tagged. KASAN instrumentation doesn't expect the sp register to be tagged, and this leads to false-positive reports. Fix by resetting the tag of kernel stack pointers after allocation. Signed-off-by: Andrey Konovalov --- kernel/fork.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/fork.c b/kernel/fork.c index d03c9586d342..9cea2265e677 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -261,7 +261,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) THREAD_SIZE_ORDER); if (likely(page)) { - tsk->stack = page_address(page); + tsk->stack = kasan_reset_tag(page_address(page)); return tsk->stack; } return NULL; @@ -302,6 +302,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, { unsigned long *stack; stack = kmem_cache_alloc_node(thread_stack_cache, THREADINFO_GFP, node); + stack = kasan_reset_tag(stack); tsk->stack = stack; return stack; } -- 2.28.0.163.g6104cc2f0b6-goog