From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0F3E825E446; Tue, 11 Mar 2025 15:10:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741705852; cv=none; b=lrJJBXH/wSXuGL+D0fVcmsdz2l/9RmfeuAQJdEpj5xXFz7YNug8gyAiF7EZhkVUmLdf8n7Ls1bIBHwfQbQljDy8mXagAnUfhRq08M5d0hQsV8mcdvLaPMHR5NnP96w21YblPw3lUChGOVRVETs0r8MiN2m8MLx8EuSx8FDd6sEk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741705852; c=relaxed/simple; bh=HHZJARZo1Lj8BUd0X9fbSiD9Qwyr4RLcwTHhqmSaGGM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IAoe38aUJwuLzv9tOdYFsVcnuPyE5Dk+UbPOnWkhfdX8bWG7PCLjoKPMjs5XPfQLNdKT0GIVPVXhggsYUtx8QnQ9aBT2aBxk45Bj1mB3VrF98eTVI0kK8VmGfTKh+HeRkVgIfHaXCw4Qz6j1C4NHmLjothZeDunVBIUZSHDrQ84= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Fud8TfTN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Fud8TfTN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D9F3C4CEE9; Tue, 11 Mar 2025 15:10:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741705851; bh=HHZJARZo1Lj8BUd0X9fbSiD9Qwyr4RLcwTHhqmSaGGM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fud8TfTNPN9bscXKpS3mVYYS3ag/6iu5zJT5ZfJGTxVuPtR4fYf9PqXpQy/oloFBv 4x2rg5pMI796/6WGdHNiXZpgDw7iEng4NTXwED3MTZauO+Mip1RAZeJo/bsQPPyUyo MyOgQA/NBxOtZGeg1F4v6GJ/u3hSCuDrROKqs3A4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andy Strohman , Sven Eckelmann , Simon Wunderlich Subject: [PATCH 5.4 177/328] batman-adv: fix panic during interface removal Date: Tue, 11 Mar 2025 15:59:07 +0100 Message-ID: <20250311145721.940935839@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145714.865727435@linuxfoundation.org> References: <20250311145714.865727435@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Strohman commit ccb7276a6d26d6f8416e315b43b45e15ee7f29e2 upstream. Reference counting is used to ensure that batadv_hardif_neigh_node and batadv_hard_iface are not freed before/during batadv_v_elp_throughput_metric_update work is finished. But there isn't a guarantee that the hard if will remain associated with a soft interface up until the work is finished. This fixes a crash triggered by reboot that looks like this: Call trace: batadv_v_mesh_free+0xd0/0x4dc [batman_adv] batadv_v_elp_throughput_metric_update+0x1c/0xa4 process_one_work+0x178/0x398 worker_thread+0x2e8/0x4d0 kthread+0xd8/0xdc ret_from_fork+0x10/0x20 (the batadv_v_mesh_free call is misleading, and does not actually happen) I was able to make the issue happen more reliably by changing hardif_neigh->bat_v.metric_work work to be delayed work. This allowed me to track down and confirm the fix. Cc: stable@vger.kernel.org Fixes: c833484e5f38 ("batman-adv: ELP - compute the metric based on the estimated throughput") Signed-off-by: Andy Strohman [sven@narfation.org: prevent entering batadv_v_elp_get_throughput without soft_iface] Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/bat_v_elp.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -65,12 +65,19 @@ static void batadv_v_elp_start_timer(str static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) { struct batadv_hard_iface *hard_iface = neigh->if_incoming; + struct net_device *soft_iface = hard_iface->soft_iface; struct ethtool_link_ksettings link_settings; struct net_device *real_netdev; struct station_info sinfo; u32 throughput; int ret; + /* don't query throughput when no longer associated with any + * batman-adv interface + */ + if (!soft_iface) + return BATADV_THROUGHPUT_DEFAULT_VALUE; + /* if the user specified a customised value for this interface, then * return it directly */ @@ -134,7 +141,7 @@ static u32 batadv_v_elp_get_throughput(s default_throughput: if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) { - batadv_info(hard_iface->soft_iface, + batadv_info(soft_iface, "WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver.\n", hard_iface->net_dev->name, BATADV_THROUGHPUT_DEFAULT_VALUE / 10,