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 F1FCFC00140 for ; Mon, 15 Aug 2022 21:05:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233342AbiHOVEd (ORCPT ); Mon, 15 Aug 2022 17:04:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346899AbiHOU4A (ORCPT ); Mon, 15 Aug 2022 16:56:00 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1120042AF7; Mon, 15 Aug 2022 12:11:29 -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 AC8496069E; Mon, 15 Aug 2022 19:11:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B82CC433D7; Mon, 15 Aug 2022 19:11:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660590688; bh=gCasWjXfyVMddZoYuo5MwQA3iAWTIDwFsCXYGZBFCo8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tXBigGMnYSr8eHb0xvt2C8V6c/8ezIcc668vLHfypVomXulpSei7TK469IOq6J18s Qbdb1BORGKDEHxax5HEpQ26VDDrm1rEryYsbRjZU8oTngbHY+0z9TYBppO126Cuh11 h4N2Y3ZC3mAXfJDyQRydWjkt0j6Rt63jWyzGmPHo= 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 5.18 0340/1095] i2c: Fix a potential use after free Date: Mon, 15 Aug 2022 19:55:39 +0200 Message-Id: <20220815180443.862632134@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180429.240518113@linuxfoundation.org> References: <20220815180429.240518113@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 d43db2c3876e..19a317fdcf5b 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -2467,8 +2467,9 @@ 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