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 D5E4A25DD0A; Tue, 11 Mar 2025 15:30:34 +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=1741707034; cv=none; b=l5ZPnwhZ37vkIzp9GgIx/JfKjagJOm8BWlKnzve+fQenExniP+EN5k4H0sFXcYbPrJHODtRrIXBhPG9SC1V0orYuRQqqw9szR3q0Ln/U23U8qHrqTOXpgI7C5SOAotNSXgMPg+lDAwDR0IQLc2J3F9UlovzJs6ci7Crs4wdvcRc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741707034; c=relaxed/simple; bh=zQ3UnIiHw/hDFJgcQS7LJIdy3Dn/JQQUNfdAxcLa5sU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CD/5MMBOp7qwVnO7T5tIbb1diVX0LUuNl1kLv+W5pmSssHcdRb4Ci4NFSt6ANhSuMm82lkjtqh/G9cN47VWNsAyYZK3A9y3ND/qzB0L7WWIWei6e7sK8yxERtyJa3/Iuvz4sxXzqO798Es50mh7DXN22fN3Y91uTAdwnC4Y8s9c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=B6JRLTYB; 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="B6JRLTYB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D3FDC4CEE9; Tue, 11 Mar 2025 15:30:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741707034; bh=zQ3UnIiHw/hDFJgcQS7LJIdy3Dn/JQQUNfdAxcLa5sU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B6JRLTYBaYzJNA2R/r1PQCtNhxRRfPbKfLtcXtvefdwIqk72T72+Qy1hjPTrlm3rh 8aCGGVXKKtwLZ1w8bCJGMGPk0hUwVYfQwbieyBwb0g8oilIuBzCwkezcQgoumM/0Me FMAbstGIBRqHuIAArvSZqB2HzCC8d8enCLo2MTrY= 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 5.10 244/462] batman-adv: fix panic during interface removal Date: Tue, 11 Mar 2025 15:58:30 +0100 Message-ID: <20250311145808.006708854@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145758.343076290@linuxfoundation.org> References: <20250311145758.343076290@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 5.10-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 @@ -66,12 +66,19 @@ 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 */ @@ -142,7 +149,7 @@ 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,