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 D5486C433DF for ; Tue, 4 Aug 2020 12:42:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1821208A9 for ; Tue, 4 Aug 2020 12:42:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="e/emAKRK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728107AbgHDMmF (ORCPT ); Tue, 4 Aug 2020 08:42:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725864AbgHDMlh (ORCPT ); Tue, 4 Aug 2020 08:41:37 -0400 Received: from mail-wr1-x44a.google.com (mail-wr1-x44a.google.com [IPv6:2a00:1450:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E59FC061756 for ; Tue, 4 Aug 2020 05:41:37 -0700 (PDT) Received: by mail-wr1-x44a.google.com with SMTP id w1so10620302wro.4 for ; Tue, 04 Aug 2020 05:41:37 -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=FcKp4QRyFHBBCVHpXykl5mFo5C8EtuBz90+P1+03xoY=; b=e/emAKRKbJkdBeq2q9WKmzagPJvb8gdtqflMVkfA9U+GObzCW9ZK8iDv+fm06/lNOH ajIRbU5BrRbTrBBREu3uaJou2xzNyaOCp+XZbidInFpetFzQFW1x8pTzoRCyj341z+Lk wq4m5lWgeLtpP7STH34Cb53cG+ae0e77L4MzJmeQ/HMqzyEcxWEcW0LZlOw/BlZk7uoa dO5RcM67ErBDoGmZ9vvLhQ54jnpx36h7CmzrXwZGP0KVeFdh2JE5X6xOlJdqsCGf3JGH qx57794JnfkOQH/j1i6yWfIbZmc2qfK2k0FRmQtkn8Nc1oWCF+4s0O93QqCimgEugC/p C7cQ== 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=FcKp4QRyFHBBCVHpXykl5mFo5C8EtuBz90+P1+03xoY=; b=T+E/nviJblbUEV0Prx70Xsgx1ApBJNpPd0uj9w40v1NDUwb5NmaYxHxJ4hjTy7Ld6M kxxSIJekb7wEotJ+fng+ZVtIeKoCVK7Rr/eu/YM5Qa4QdA+X+pFY66T51qTtEHZn0uxH n3PL0GSvSYMdKG3TxnnDp2wVdkpUVC/wy8lVCd1v84yco5hKMfkAJ0JowOiH+hQ6lTj6 z+BvpdX3MDs6zcaz5LpoU4JbnZqc98en5dTkufW0RYKjZMh5d1TphNlbeR/k4I0UVdDf OOkz0LtdC6kyTeFLxSUwacYtG2qyjTybbS0FxN5s2MH78Jqvmg1tIDHOTfpN/odRcs1L izdw== X-Gm-Message-State: AOAM531AnbhpC7JoP6aDHoFdxQ7GRVvd2JLqFGgM6+Ridp9bPbtnvv/2 mCzE4mQDchj1FwzpQ4I8wLfVCKdjcAygg/L6 X-Google-Smtp-Source: ABdhPJysUQ4oDqsJhy6xq9sHQOykVWtKsRJrE3eJ3umL4PptPqQvdYk0j95C1HF2RsOBJ7cfXSW95HsjwlUjMNSy X-Received: by 2002:a1c:b443:: with SMTP id d64mr4329306wmf.68.1596544895842; Tue, 04 Aug 2020 05:41:35 -0700 (PDT) Date: Tue, 4 Aug 2020 14:41:24 +0200 In-Reply-To: Message-Id: <12d8c678869268dd0884b01271ab592f30792abf.1596544734.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.28.0.163.g6104cc2f0b6-goog Subject: [PATCH v2 1/5] kasan: don't tag stacks allocated with pagealloc From: Andrey Konovalov To: Andrew Morton Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Marco Elver , Ard Biesheuvel , Arvind Sankar , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-efi@vger.kernel.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 efc5493203ae..75415f5e647c 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; @@ -307,6 +307,7 @@ 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