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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 255B6C433F5 for ; Thu, 2 Sep 2021 21:57:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A39860E8B for ; Thu, 2 Sep 2021 21:57:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347938AbhIBV6x (ORCPT ); Thu, 2 Sep 2021 17:58:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:54486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243139AbhIBV6w (ORCPT ); Thu, 2 Sep 2021 17:58:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BDAAF6056B; Thu, 2 Sep 2021 21:57:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1630619874; bh=W5UlXSXOIa4cHd1UZpUTIGQO5HZZUOKbYIsO69xw2R4=; h=Date:From:To:Subject:In-Reply-To:From; b=HuKqzstWiIPamkcSWK1GkzSJ03PE96MEk30BM6aBAjm8bqVU6NTb1sOxNF54h5swD zK+Cap/ghcuKqfSk9WVN5+t2h8mnIa8PVa9xJe7ciyfdZaQOFROxDDVD1WU8tbLf8K xg4ZyrP8NApYmQDqJ+j1Hqm6RALgCNCfqg8Fdj28= Date: Thu, 02 Sep 2021 14:57:53 -0700 From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@gmail.com, aryabinin@virtuozzo.com, dvyukov@google.com, elver@google.com, glider@google.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 149/212] kasan: test: avoid corrupting memory in kasan_rcu_uaf Message-ID: <20210902215753.m2qklrGfI%akpm@linux-foundation.org> In-Reply-To: <20210902144820.78957dff93d7bea620d55a89@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Andrey Konovalov Subject: kasan: test: avoid corrupting memory in kasan_rcu_uaf kasan_rcu_uaf() writes to freed memory via kasan_rcu_reclaim(), which is only safe with the GENERIC mode (as it uses quarantine). For other modes, this test corrupts kernel memory, which might result in a crash. Turn the write into a read. Link: https://lkml.kernel.org/r/b6f2c3bf712d2457c783fa59498225b66a634f62.1628779805.git.andreyknvl@gmail.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Signed-off-by: Andrew Morton --- lib/test_kasan_module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/test_kasan_module.c~kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf +++ a/lib/test_kasan_module.c @@ -71,7 +71,7 @@ static noinline void __init kasan_rcu_re struct kasan_rcu_info, rcu); kfree(fp); - fp->i = 1; + ((volatile struct kasan_rcu_info *)fp)->i; } static noinline void __init kasan_rcu_uaf(void) _