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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 7BF4CC433EF for ; Fri, 10 Sep 2021 00:42:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65E7F61108 for ; Fri, 10 Sep 2021 00:42:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241222AbhIJAnt (ORCPT ); Thu, 9 Sep 2021 20:43:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:45786 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233130AbhIJAT2 (ORCPT ); Thu, 9 Sep 2021 20:19:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 68F7E610A3; Fri, 10 Sep 2021 00:18:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233098; bh=dcMN18hCQ+HoYY7mN0kEg/7owgCb7/zijP7JEOL6MuU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SMICO8jKDABAbQp+wiiLcwDXlQWM+dQEOAhkR38OOIppRqANQ20WNKLWVSBaBg4gr M/j554nGTpWCD2d2Y5zIyvlq+JiQ2nx5IXi9G9rGg32QBBKLRTrOHrncJP00XJe/Yt qdC7DRVlCPl+ZlO3h0ivuKBurkwD84JHeoifwCcq+kO89KjBwoCeQW12ere8q2i5AA Co61wH/HQotRh99JJT5TlvsHpV2jv0DG25c1HOSU3ooUnUG27l9vOuhWNU++o9+u/t w7dAlXMwyHyNQOOzRymzuIv1sY1402i2jAMj+FnHOL7BJgxeHcOundq0D1TNxPNRhA 5QQoAkY55SLhw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andrey Konovalov , Marco Elver , Alexander Potapenko , Andrey Ryabinin , Dmitry Vyukov , Andrew Morton , Linus Torvalds , Sasha Levin , kasan-dev@googlegroups.com Subject: [PATCH AUTOSEL 5.14 99/99] kasan: test: avoid corrupting memory in kasan_rcu_uaf Date: Thu, 9 Sep 2021 20:15:58 -0400 Message-Id: <20210910001558.173296-99-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910001558.173296-1-sashal@kernel.org> References: <20210910001558.173296-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andrey Konovalov [ Upstream commit f16de0bcdb55bf18e2533ca625f3e4b4952f254c ] 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 Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- lib/test_kasan_module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c index fa73b9df0be4..7ebf433edef3 100644 --- a/lib/test_kasan_module.c +++ b/lib/test_kasan_module.c @@ -71,7 +71,7 @@ static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp) 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) -- 2.30.2