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 7FD20C38159 for ; Tue, 23 Aug 2022 11:27:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357626AbiHWL0f (ORCPT ); Tue, 23 Aug 2022 07:26:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357746AbiHWLVE (ORCPT ); Tue, 23 Aug 2022 07:21:04 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A37188C010; Tue, 23 Aug 2022 02:22:52 -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 sin.source.kernel.org (Postfix) with ESMTPS id B153ACE1B5A; Tue, 23 Aug 2022 09:22:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB3BCC433C1; Tue, 23 Aug 2022 09:22:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661246569; bh=kDQvoALiwbXOtZbi36c5Qj8hpGlknv2dFFzCTSNrSQY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qR1rIV/S0eEwRDD9iwj90EeFu0QwdnaXxXYSno62YQGBE7SwSy1N07LVgPQiA6VWF p49smYVAOQOevOEIyXSqVjRadsFmIx8vK8i9lpai95m0IihTC4VAPZvXdVwq79Ryp2 C3mgSjgS23GdxTeegWGbviX8nAwU3XjrF/4LeQgc= 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 5.4 151/389] net: rose: fix netdev reference changes Date: Tue, 23 Aug 2022 10:23:49 +0200 Message-Id: <20220823080121.910594626@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 = 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 6a0df7c8a939..95dda29058a0 100644 --- a/net/rose/af_rose.c +++ b/net/rose/af_rose.c @@ -169,6 +169,7 @@ 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 = NULL; } } @@ -569,6 +570,8 @@ static struct sock *rose_make_new(struct sock *osk) rose->idle = orose->idle; rose->defer = orose->defer; rose->device = orose->device; + if (rose->device) + dev_hold(rose->device); rose->qbitincl = orose->qbitincl; return sk; @@ -622,6 +625,7 @@ static int rose_release(struct socket *sock) break; } + dev_put(rose->device); sock->sk = NULL; release_sock(sk); sock_put(sk); @@ -698,7 +702,6 @@ static int rose_connect(struct socket *sock, struct sockaddr *uaddr, int addr_le struct rose_sock *rose = rose_sk(sk); struct sockaddr_rose *addr = (struct sockaddr_rose *)uaddr; unsigned char cause, diagnostic; - struct net_device *dev; ax25_uid_assoc *user; int n, err = 0; @@ -755,9 +758,12 @@ static int rose_connect(struct socket *sock, struct sockaddr *uaddr, int addr_le } if (sock_flag(sk, SOCK_ZAPPED)) { /* Must bind first - autobinding in this may or may not work */ + struct net_device *dev; + sock_reset_flag(sk, SOCK_ZAPPED); - if ((dev = rose_dev_first()) == NULL) { + dev = rose_dev_first(); + if (!dev) { err = -ENETUNREACH; goto out_release; } @@ -765,6 +771,7 @@ static int rose_connect(struct socket *sock, struct sockaddr *uaddr, int addr_le user = ax25_findbyuid(current_euid()); if (!user) { err = -EINVAL; + dev_put(dev); goto out_release; } diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c index 5f32113c9bbd..64d441d3b653 100644 --- a/net/rose/rose_route.c +++ b/net/rose/rose_route.c @@ -613,6 +613,8 @@ struct net_device *rose_dev_first(void) if (first == NULL || strncmp(dev->name, first->name, 3) < 0) first = dev; } + if (first) + dev_hold(first); rcu_read_unlock(); return first; -- 2.35.1