From nobody Fri Sep 5 20:16:51 2025 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 218ADC32772 for ; Tue, 23 Aug 2022 11:24:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243629AbiHWLY3 (ORCPT ); Tue, 23 Aug 2022 07:24:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242769AbiHWLRu (ORCPT ); Tue, 23 Aug 2022 07:17:50 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 487BD89833; Tue, 23 Aug 2022 02:21:49 -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 ams.source.kernel.org (Postfix) with ESMTPS id E3422B81B1F; Tue, 23 Aug 2022 09:21:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53CCFC433D6; Tue, 23 Aug 2022 09:21:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661246507; bh=Ha3JHNhNor1v7npzwIe3xBvpftvLvAA3ue4W83hWoUg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gvoru/MAO0oGWdUa69igQRuuHCzJljUnOgyQBW2shX+TZvu0JOYattBKBU5L3csRU 8x5gxqxs5HDt0Rl/ca4/sSy4ALyc+HbUKyijIDWmeJvK6nThEgduQNLEOHjxtkKcN+ LAymIduI2kmNfjkQCxoYEXjuNaqAJqlzcqIqrkXI= 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 5.4 101/389] i2c: Fix a potential use after free Date: Tue, 23 Aug 2022 10:22:59 +0200 Message-Id: <20220823080119.836724149@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080115.331990024@linuxfoundation.org> References: <20220823080115.331990024@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 1b93fae58ec7..964e8a29b27b 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -2358,8 +2358,9 @@ void i2c_put_adapter(struct i2c_adapter *adap) if (!adap) return; =20 - 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); =20 --=20 2.35.1