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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBD79C28B2B for ; Fri, 19 Aug 2022 16:07:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351393AbiHSQHK (ORCPT ); Fri, 19 Aug 2022 12:07:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351665AbiHSQCV (ORCPT ); Fri, 19 Aug 2022 12:02:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F6D7D5DDA; Fri, 19 Aug 2022 08:54:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 78FDA6174E; Fri, 19 Aug 2022 15:54:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82052C433D6; Fri, 19 Aug 2022 15:54:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660924456; bh=0KI5vd+6+LH5ocNJ+0VWyFQYkD7hG6+mjvTzDV8Zyvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pZXRAbmgRqluOI/iyoAgY9668cO1qVp0fWfkuZ9slHnCGZ3or02vukV3tkwRrrmHL 4pAtD9tBOAPez90PitLuobkIrKXQjXtR+gHt+iR+MzpD914c0FYdsxafzgRtQ/b5nR Im2Zpx6F0QG3SVcMhjquVzI9ya/geR4A6rCTSHq8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xu Wang , Wolfram Sang , Sasha Levin Subject: [PATCH 5.10 176/545] i2c: Fix a potential use after free Date: Fri, 19 Aug 2022 17:39:06 +0200 Message-Id: <20220819153837.224799533@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220819153829.135562864@linuxfoundation.org> References: <20220819153829.135562864@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xu Wang [ Upstream commit e4c72c06c367758a14f227c847f9d623f1994ecf ] Free the adap structure only after we are done using it. This patch just moves the put_device() down a bit to avoid the use after free. Fixes: 611e12ea0f12 ("i2c: core: manage i2c bus device refcount in i2c_[get|put]_adapter") Signed-off-by: Xu Wang [wsa: added comment to the code, added Fixes tag] Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/i2c-core-base.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index bdce6d3e5327..34fecf97a355 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -2405,8 +2405,9 @@ void i2c_put_adapter(struct i2c_adapter *adap) if (!adap) return; - put_device(&adap->dev); module_put(adap->owner); + /* Should be last, otherwise we risk use-after-free with 'adap' */ + put_device(&adap->dev); } EXPORT_SYMBOL(i2c_put_adapter); -- 2.35.1