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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 56325C433E0 for ; Fri, 22 Jan 2021 14:48:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CC92239D1 for ; Fri, 22 Jan 2021 14:48:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728890AbhAVOsJ (ORCPT ); Fri, 22 Jan 2021 09:48:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:41480 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728672AbhAVOY7 (ORCPT ); Fri, 22 Jan 2021 09:24:59 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id ECFAA23BAD; Fri, 22 Jan 2021 14:19:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611325147; bh=MGRImWCa37Xlup1zSYHj2aC6xi2m8z+FnyF8KGvaLEE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FboWpXpMbcf9aeXuXghKCRJyYkCJoB/fQ0ux+7/w9zdnPf0RPWwvaq7vX1qg3nxdl hVKg00zWE8qYHLWLum/DwvXXRUH4O12Deaq7iVfd5Qclpm61M1KxEq1pjfVwOZLIoh UJRLSH/VIy69JljSuZYNgVAu1krixg6jgWj3EbIQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vladimir Oltean , Florian Fainelli , Jakub Kicinski Subject: [PATCH 5.10 33/43] net: dsa: clear devlink port type before unregistering slave netdevs Date: Fri, 22 Jan 2021 15:12:49 +0100 Message-Id: <20210122135737.002440864@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122135735.652681690@linuxfoundation.org> References: <20210122135735.652681690@linuxfoundation.org> User-Agent: quilt/0.66 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: Vladimir Oltean [ Upstream commit 91158e1680b164c8d101144ca916a3dca10c3e17 ] Florian reported a use-after-free bug in devlink_nl_port_fill found with KASAN: (devlink_nl_port_fill) (devlink_port_notify) (devlink_port_unregister) (dsa_switch_teardown.part.3) (dsa_tree_teardown_switches) (dsa_unregister_switch) (bcm_sf2_sw_remove) (platform_remove) (device_release_driver_internal) (device_links_unbind_consumers) (device_release_driver_internal) (device_driver_detach) (unbind_store) Allocated by task 31: alloc_netdev_mqs+0x5c/0x50c dsa_slave_create+0x110/0x9c8 dsa_register_switch+0xdb0/0x13a4 b53_switch_register+0x47c/0x6dc bcm_sf2_sw_probe+0xaa4/0xc98 platform_probe+0x90/0xf4 really_probe+0x184/0x728 driver_probe_device+0xa4/0x278 __device_attach_driver+0xe8/0x148 bus_for_each_drv+0x108/0x158 Freed by task 249: free_netdev+0x170/0x194 dsa_slave_destroy+0xac/0xb0 dsa_port_teardown.part.2+0xa0/0xb4 dsa_tree_teardown_switches+0x50/0xc4 dsa_unregister_switch+0x124/0x250 bcm_sf2_sw_remove+0x98/0x13c platform_remove+0x44/0x5c device_release_driver_internal+0x150/0x254 device_links_unbind_consumers+0xf8/0x12c device_release_driver_internal+0x84/0x254 device_driver_detach+0x30/0x34 unbind_store+0x90/0x134 What happens is that devlink_port_unregister emits a netlink DEVLINK_CMD_PORT_DEL message which associates the devlink port that is getting unregistered with the ifindex of its corresponding net_device. Only trouble is, the net_device has already been unregistered. It looks like we can stub out the search for a corresponding net_device if we clear the devlink_port's type. This looks like a bit of a hack, but also seems to be the reason why the devlink_port_type_clear function exists in the first place. Fixes: 3122433eb533 ("net: dsa: Register devlink ports before calling DSA driver setup()") Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Tested-by: Florian fainelli Reported-by: Florian Fainelli Link: https://lore.kernel.org/r/20210112004831.3778323-1-olteanv@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/dsa/dsa2.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -353,9 +353,13 @@ static int dsa_port_devlink_setup(struct static void dsa_port_teardown(struct dsa_port *dp) { + struct devlink_port *dlp = &dp->devlink_port; + if (!dp->setup) return; + devlink_port_type_clear(dlp); + switch (dp->type) { case DSA_PORT_TYPE_UNUSED: break;