From patchwork Tue Jun 9 17:44:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 224603 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 D19A8C433E1 for ; Tue, 9 Jun 2020 18:23:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5BF02067B for ; Tue, 9 Jun 2020 18:23:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591727013; bh=ps8pnlBp1WwH8dOmL2uAK8jQRRYb/JbeuNB5BmVB1l0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=N4oag/a/zaphI29fHPeuQq7uNsRVRW0zMvuHjHMomBXYADcXHLsQqYuO4Tx72+EYK 1Po06VnARSLPUlQqJq74SrZLSI0h8LPbCVwE2JeTxksiuQMF1131lijsmQEDptRSjh uRi9dWazyT0KfmwID3oWzKoQYgfluG7vV6RB8Odg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732105AbgFISXa (ORCPT ); Tue, 9 Jun 2020 14:23:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:58670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732090AbgFIRrY (ORCPT ); Tue, 9 Jun 2020 13:47:24 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2D13D20823; Tue, 9 Jun 2020 17:47:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591724844; bh=ps8pnlBp1WwH8dOmL2uAK8jQRRYb/JbeuNB5BmVB1l0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z+z4vdbCsZK8ZTXQA/RurSSylVPPisUzCsmSFsabfi8KT3VMT04kxxLPNp4dq/rsx PXA1gabhethlfHQDhYGkofsRmOgrFK9PkKjEMrjYLyLgvQZ9jZkfVkcgI15mh2QGQG ehd33yZCFY1pL+Hva+4Uhxz63xQxNcWq05W7Z8/4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, yangerkun , Ben Hutchings Subject: [PATCH 4.4 16/36] slcan: Fix double-free on slcan_open() error path Date: Tue, 9 Jun 2020 19:44:16 +0200 Message-Id: <20200609173934.205737358@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200609173933.288044334@linuxfoundation.org> References: <20200609173933.288044334@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ben Hutchings Commit 9ebd796e2400 ("can: slcan: Fix use-after-free Read in slcan_open") was incorrectly backported to 4.4 and 4.9 stable branches. Since they do not have commit cf124db566e6 ("net: Fix inconsistent teardown and release of private netdev state."), the destructor function slc_free_netdev() is already responsible for calling free_netdev() and slcan_open() must not call both of them. yangerkun previously fixed the same bug in slip. Fixes: ce624b2089ea ("can: slcan: Fix use-after-free Read in slcan_open") # 4.4 Fixes: f59604a80fa4 ("slcan: not call free_netdev before rtnl_unlock ...") # 4.4 Fixes: 56635a1e6ffb ("can: slcan: Fix use-after-free Read in slcan_open") # 4.9 Fixes: a1c9b23142ac ("slcan: not call free_netdev before rtnl_unlock ...") # 4.9 Cc: yangerkun Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/slcan.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -618,10 +618,9 @@ err_free_chan: sl->tty = NULL; tty->disc_data = NULL; clear_bit(SLF_INUSE, &sl->flags); - slc_free_netdev(sl->dev); /* do not call free_netdev before rtnl_unlock */ rtnl_unlock(); - free_netdev(sl->dev); + slc_free_netdev(sl->dev); return err; err_exit: