From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dvalin.narfation.org (dvalin.narfation.org [213.160.73.56]) (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 2E9C13A1690 for ; Fri, 29 May 2026 18:15:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.160.73.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780078522; cv=none; b=ZvGJZe2aIUxFjER/Sa7XwIA+9SPfowvoZaDAscY37L2rPSpywxSaZvL1OCJwmBtL77mCLUbG4IHrYf4zSn30CIgj7XYfTg7Fd+B3RNIhZXF9KRyCDH8ErHARWCYnz2lIsltrKDRrWT9OvlW0N1BWGQS3RxNqT2g1qCHptpvYCz4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780078522; c=relaxed/simple; bh=5Z/18GwPMPAuVvnVbaqIsK4bR8EtHz1wemM482i2oKk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EmDigLBhtulIMUS9K8STKVS8rSDbtyfBpk7y7guFNaHt//sXbq6JdwDp+6r1VJ33rNuep7Qj+Z3scM+NrTeNrQMeQNS7kh/aMCZzTyPqKJlyVrNAIL2GrNXfLu55PfG7cIbWbtfNVztzlpQdxv6bFPNQZrw582wiOEycWcYQFHA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org; spf=pass smtp.mailfrom=narfation.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b=ZTwH/zGa; arc=none smtp.client-ip=213.160.73.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=narfation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b="ZTwH/zGa" Received: by dvalin.narfation.org (Postfix) id 70EB22000E; Fri, 29 May 2026 18:15:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1780078519; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zM7NwxMpGgGkkOPREsXsTnRud2bmFnHSqFMoiKwR4U4=; b=ZTwH/zGaiCpxWrcee7YgAQb7c37bp6M1AespEI0r+R4ISQOTCs34CETtzFoSECqjpjdI6G bwd2ofXEf6x8IVFlaSmIWVJv49K9sG7DYWVb10HxG9nwl+EylveudOOYxc+1u68zsZWtM2 lL0SUDEk3Wp/XOVx+ZipdxFWzUtSkL8= From: Sven Eckelmann To: stable@vger.kernel.org Cc: Sven Eckelmann , stable@kernel.org Subject: [PATCH 6.6.y] batman-adv: tt: avoid empty VLAN responses Date: Fri, 29 May 2026 20:15:14 +0200 Message-ID: <20260529181514.416732-1-sven@narfation.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <2026052842-snugness-statutory-4b6d@gregkh> References: <2026052842-snugness-statutory-4b6d@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit commit fa1bd704940b5bcbc32c0b28db9167405c8ee5e0 upstream. The commit 16116dac2339 ("batman-adv: prevent TT request storms by not sending inconsistent TT TLVLs") added checks to the local (direct) TT response code. But the response can also be done indirectly by another node using the global TT state. To avoid such inconsistency states reported in the original fix, also avoid sending empty VLANs for replies from the global TT state. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") [ Context, drop flex array dependency ] Signed-off-by: Sven Eckelmann --- net/batman-adv/translation-table.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index d4cebe122e528..4045ddefc29b4 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -843,17 +843,19 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, s32 *tt_len) { u16 num_vlan = 0; - u16 num_entries = 0; u16 tvlv_len = 0; unsigned int change_offset; struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_orig_node_vlan *vlan; + u16 total_entries = 0; u8 *tt_change_ptr; + int vlan_entries; spin_lock_bh(&orig_node->vlan_list_lock); hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + total_entries += vlan_entries; num_vlan++; - num_entries += atomic_read(&vlan->tt.num_entries); } change_offset = sizeof(**tt_data); @@ -861,7 +863,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, /* if tt_len is negative, allocate the space needed by the full table */ if (*tt_len < 0) - *tt_len = batadv_tt_len(num_entries); + *tt_len = batadv_tt_len(total_entries); if (change_offset > U16_MAX || *tt_len > U16_MAX - change_offset) { *tt_len = 0; @@ -882,14 +884,27 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, (*tt_data)->num_vlan = htons(num_vlan); tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); + num_vlan = 0; hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { + vlan_entries = atomic_read(&vlan->tt.num_entries); + if (vlan_entries < 1) + continue; + tt_vlan->vid = htons(vlan->vid); tt_vlan->crc = htonl(vlan->tt.crc); tt_vlan->reserved = 0; tt_vlan++; + num_vlan++; } + /* recalculate in case number of VLANs reduced */ + change_offset = sizeof(**tt_data); + change_offset += num_vlan * sizeof(*tt_vlan); + tvlv_len = *tt_len + change_offset; + + (*tt_data)->num_vlan = htons(num_vlan); + tt_change_ptr = (u8 *)*tt_data + change_offset; *tt_change = (struct batadv_tvlv_tt_change *)tt_change_ptr; -- 2.47.3