From nobody Wed Dec 17 09:14:57 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 85263C32772 for ; Tue, 23 Aug 2022 10:45:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355751AbiHWKpT (ORCPT ); Tue, 23 Aug 2022 06:45:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355734AbiHWKg6 (ORCPT ); Tue, 23 Aug 2022 06:36:58 -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 F0D72A6C38; Tue, 23 Aug 2022 02:07:26 -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 731A3B81C89; Tue, 23 Aug 2022 09:07:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4195C433D6; Tue, 23 Aug 2022 09:07:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661245644; bh=YrtYR5uzYTGHvW1l1duOpFLg7RFtdbzcLZIhVMmPlcc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HooSGEnZeecdagB0+kQsxM506ftYGTKw+34qGWFlpYuKQNNtOZMxfXyCfcWKYKaOv FY65ThT6U2ttUvQUanpY+nJC8bh4qnmb5bnTtt/uGuCHXriY8K3k9PAydYZ5nSQ5Sw Z+b6E4VU7eU6P0KTWr1XVFcdLrAHdZ2xfB7AciG4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bernard Pidoux , Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 111/287] net: rose: fix netdev reference changes Date: Tue, 23 Aug 2022 10:24:40 +0200 Message-Id: <20220823080104.106110987@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080100.268827165@linuxfoundation.org> References: <20220823080100.268827165@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: Eric Dumazet [ Upstream commit 931027820e4dafabc78aff82af59f8c1c4bd3128 ] Bernard reported that trying to unload rose module would lead to infamous messages: unregistered_netdevice: waiting for rose0 to become free. Usage count =3D xx This patch solves the issue, by making sure each socket referring to a netdevice holds a reference count on it, and properly releases it in rose_release(). rose_dev_first() is also fixed to take a device reference before leaving the rcu_read_locked section. Following patch will add ref_tracker annotations to ease future bug hunting. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Bernard Pidoux Signed-off-by: Eric Dumazet Tested-by: Bernard Pidoux Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/rose/af_rose.c | 11 +++++++++-- net/rose/rose_route.c | 2 ++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c index d00a0ef39a56..03a1ee221112 100644 --- a/net/rose/af_rose.c +++ b/net/rose/af_rose.c @@ -194,6 +194,7 @@ static void rose_kill_by_device(struct net_device *dev) rose_disconnect(s, ENETUNREACH, ROSE_OUT_OF_ORDER, 0); if (rose->neighbour) rose->neighbour->use--; + dev_put(rose->device); rose->device =3D NULL; } } @@ -594,6 +595,8 @@ static struct sock *rose_make_new(struct sock *osk) rose->idle =3D orose->idle; rose->defer =3D orose->defer; rose->device =3D orose->device; + if (rose->device) + dev_hold(rose->device); rose->qbitincl =3D orose->qbitincl; =20 return sk; @@ -647,6 +650,7 @@ static int rose_release(struct socket *sock) break; } =20 + dev_put(rose->device); sock->sk =3D NULL; release_sock(sk); sock_put(sk); @@ -721,7 +725,6 @@ static int rose_connect(struct socket *sock, struct soc= kaddr *uaddr, int addr_le struct rose_sock *rose =3D rose_sk(sk); struct sockaddr_rose *addr =3D (struct sockaddr_rose *)uaddr; unsigned char cause, diagnostic; - struct net_device *dev; ax25_uid_assoc *user; int n, err =3D 0; =20 @@ -778,9 +781,12 @@ static int rose_connect(struct socket *sock, struct so= ckaddr *uaddr, int addr_le } =20 if (sock_flag(sk, SOCK_ZAPPED)) { /* Must bind first - autobinding in thi= s may or may not work */ + struct net_device *dev; + sock_reset_flag(sk, SOCK_ZAPPED); =20 - if ((dev =3D rose_dev_first()) =3D=3D NULL) { + dev =3D rose_dev_first(); + if (!dev) { err =3D -ENETUNREACH; goto out_release; } @@ -788,6 +794,7 @@ static int rose_connect(struct socket *sock, struct soc= kaddr *uaddr, int addr_le user =3D ax25_findbyuid(current_euid()); if (!user) { err =3D -EINVAL; + dev_put(dev); goto out_release; } =20 diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c index 46ae92d70324..5671853bef83 100644 --- a/net/rose/rose_route.c +++ b/net/rose/rose_route.c @@ -616,6 +616,8 @@ struct net_device *rose_dev_first(void) if (first =3D=3D NULL || strncmp(dev->name, first->name, 3) < 0) first =3D dev; } + if (first) + dev_hold(first); rcu_read_unlock(); =20 return first; --=20 2.35.1