From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794591302; b=HSs1N1msoVKrkoRQxEGYjjCKJ7ZZZkIrtCAQPv4oD2YOFQES/DEox+US7n9hOtZf77ay mIgqe2bc0WLDmw2qNjGtLzggfDUbSJdc1nI0MB5kWoD1U2fGFtGkr/yymuRMF23WO2zgr QaQI3mUOLR6f+xqHBi0jRMdKPjIYG+sz3n3nFoR1RzNL56EzOiX4fT7WApftKmqAm0UgJ yUC0f/a+PozbYkdn36PHacm7wxmHrLhM0Hh7+sREfI7mOggC5H8z0SINLkGBIWrRHwyNG /i4YkQS3EOPUUYCuo/h51mM9Q6Y9odQtJgGSNsZhQVjQRMFx4db+sQXqLT5MyZR6ZtQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794591302; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=ys0yMWAeY9yaaaiObzGcZC8cucxoKUjk1fFd6QLwo4Y=; b=2jpuTNYeDfSR4yJANT2V7b/6CmNMLQY6RCcUFklt2tV1RKR5Z8HA47olNfePqXKrjF4R t4DDC8ScrEX/d0Ch+0NLL1NHr2DV5BuwvN3Y4guiYekHV8ecOTgMxablhH11HG7iY9EuD Z3ZxuZTMoK/NsrGvi2e2NflN3ZEzAtS9ADLQ0UQjFeyyx4eXvYAYofqbZaSZGulUKj/2z ALnBJeylTiLVvM7Xtv7CZ/3Sg43Knjf5NhN6pqc/z1A2rjAEjI9yzKKiQcwSfvxCZOSpu cRk9PyaXfIEDHpXV0mGXdbTEHCuEuhE3Ufwr5SX4evsz2OzQAlDqtq75kLxVFP4d5vA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=alQ7plvm; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4D8CD6077D6E; Fri, 13 Nov 2026 17:35:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=alQ7plvm Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECB181F000C4; Fri, 13 Nov 2026 17:35:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794591302; bh=ys0yMWAeY9yaaaiObzGcZC8cucxoKUjk1fFd6QLwo4Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=alQ7plvmOyFa5fjF+d4dBw+ltINrCbRSXdhbFUEfXI8vqzne9skcODx6hnfmEjLr6 C0ZDfb9HHaBjvjZRbYFJJ1raX/is2q7H02jog9bM/Mr7WYCDm/7IKXMmYclni9mooF ow0sTJW/67wcMTsQLXamu1yDUEeNtjy21h4jvlaw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Sven Eckelmann , Sasha Levin Subject: [PATCH 6.12 417/670] batman-adv: tt: dont drop local events queued during TVLV update Date: Fri, 13 Nov 2026 10:49:41 -0500 Message-ID: <20261113153825.875439108@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit ed7a0dfdd370acb48be7a281df732c1bebcc7f1d upstream. batadv_tt_tvlv_container_update() read the number of local changes without holding changes_list_lock. batadv_tt_local_event() is not serialized by the commit_lock and can queue new events before the changes_list is flushed: CPU0 CPU1 batadv_tt_tvlv_container_update() num = ...local_changes; batadv_tt_local_event() list_add_tail(...); ...local_changes++; spin_lock_bh(&...changes_list_lock); /* only num events copied but all freed */ The additional events were freed without ever being sent. Other nodes will only notice this via a CRC mismatch and must request the full table. The number of changes and the changes_list must therefore be taken atomically. Events queued afterwards then stay in the tt.changes_list for the next TT round. The changes can no longer be kept for the next round when the TVLV buffer allocation fails. But they would be sent with a skipped TTVN anyway, so the other nodes have to request the full table in this case either way. The last changeset is only dropped in this case when the TTVN was incremented. Without new changes, it still describes the current TTVN. Previously, the unconsumed changes caused a retry of the TVLV container update in the next commit round. Since the changes are now consumed, the next round would only take the path without changes and wait for BATADV_TT_OGM_APPEND_MAX rounds before updating the container again. Until then, the outdated container with the previous TTVN would still be announced. The ogm_append_cnt is therefore reset on failure to retry the update in the next OGM interval. This doesn't make the CRC consistent with the announced changeset. The local table modifications are still not serialized with the commit and batadv_tt_local_transition_new() can still make a client part of the CRC for which the event is only part of the next TT round. Such an inconsistency is detected by the CRC check of the other nodes and solved via a full table request. Cc: stable@vger.kernel.org Reported-by: Sashiko Closes: https://sashiko.dev/#/bug/linux-fc286ddd-5bed-4683-b842-ee7a307eeb19 Fixes: a73105b8d4c7 ("batman-adv: improved client announcement mechanism") [ Context, switch to old "mesh_iface" name "soft_iface", access local_changes with atomic_t helpers ] Signed-off-by: Sven Eckelmann Signed-off-by: Sasha Levin --- net/batman-adv/translation-table.c | 61 +++++++++++++++++++++++------- 1 file changed, 48 insertions(+), 13 deletions(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 031f9bd8f72dd..c3331304cc394 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -1019,20 +1019,22 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, * batadv_tt_tvlv_container_update() - update the translation table tvlv * container after local tt changes have been committed * @bat_priv: the bat priv with all the soft interface information + * @changes_list: list of committed changes which will be consumed + * @tt_diff_entries_num: number of entries in @changes_list */ -static void batadv_tt_tvlv_container_update(struct batadv_priv *bat_priv) +static void batadv_tt_tvlv_container_update(struct batadv_priv *bat_priv, + struct list_head *changes_list, + int tt_diff_entries_num) { struct batadv_tt_change_node *entry, *safe; struct batadv_tvlv_tt_data *tt_data; struct batadv_tvlv_tt_change *tt_change; int tt_diff_len, tt_change_len = 0; - int tt_diff_entries_num = 0; int tt_diff_entries_count = 0; bool drop_changes = false; size_t tt_extra_len = 0; u16 tvlv_len; - tt_diff_entries_num = atomic_read(&bat_priv->tt.local_changes); tt_diff_len = batadv_tt_len(tt_diff_entries_num); /* if we have too many changes for one packet don't send any @@ -1050,19 +1052,39 @@ static void batadv_tt_tvlv_container_update(struct batadv_priv *bat_priv) tvlv_len = batadv_tt_prepare_tvlv_local_data(bat_priv, &tt_data, &tt_change, &tt_diff_len); - if (!tvlv_len) + if (!tvlv_len) { + /* the changes are lost and the other nodes have to request the + * full table. Don't answer TT requests for the new TTVN with + * the stale changeset of the previous TTVN. Without changes, the + * TTVN was not incremented and the last changeset is still valid + */ + if (drop_changes || tt_diff_entries_num > 0) { + list_for_each_entry_safe(entry, safe, changes_list, + list) { + list_del(&entry->list); + kmem_cache_free(batadv_tt_change_cache, entry); + } + + spin_lock_bh(&bat_priv->tt.last_changeset_lock); + kfree(bat_priv->tt.last_changeset); + bat_priv->tt.last_changeset = NULL; + bat_priv->tt.last_changeset_len = 0; + spin_unlock_bh(&bat_priv->tt.last_changeset_lock); + } + + /* announce the already committed TTVN in the next OGM interval + * instead of waiting for BATADV_TT_OGM_APPEND_MAX idle rounds + */ + atomic_set(&bat_priv->tt.ogm_append_cnt, 0); return; + } tt_data->flags = BATADV_TT_OGM_DIFF; if (!drop_changes && tt_diff_len == 0) goto container_register; - spin_lock_bh(&bat_priv->tt.changes_list_lock); - atomic_set(&bat_priv->tt.local_changes, 0); - - list_for_each_entry_safe(entry, safe, &bat_priv->tt.changes_list, - list) { + list_for_each_entry_safe(entry, safe, changes_list, list) { if (tt_diff_entries_count < tt_diff_entries_num) { memcpy(tt_change + tt_diff_entries_count, &entry->change, @@ -1072,7 +1094,6 @@ static void batadv_tt_tvlv_container_update(struct batadv_priv *bat_priv) list_del(&entry->list); kmem_cache_free(batadv_tt_change_cache, entry); } - spin_unlock_bh(&bat_priv->tt.changes_list_lock); tt_extra_len = batadv_tt_len(tt_diff_entries_num - tt_diff_entries_count); @@ -3761,11 +3782,25 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv) */ static void batadv_tt_local_commit_changes_nolock(struct batadv_priv *bat_priv) { + LIST_HEAD(changes_list); + int changes_num; + lockdep_assert_held(&bat_priv->tt.commit_lock); - if (atomic_read(&bat_priv->tt.local_changes) < 1) { + /* atomically get the list of changes. The TTVN decision and the + * announced changeset must cover the same events. Events queued + * afterwards stay in the tt.changes_list for the next TT round + */ + spin_lock_bh(&bat_priv->tt.changes_list_lock); + list_splice_init(&bat_priv->tt.changes_list, &changes_list); + changes_num = atomic_read(&bat_priv->tt.local_changes); + atomic_set(&bat_priv->tt.local_changes, 0); + spin_unlock_bh(&bat_priv->tt.changes_list_lock); + + if (changes_num == 0) { if (!batadv_atomic_dec_not_zero(&bat_priv->tt.ogm_append_cnt)) - batadv_tt_tvlv_container_update(bat_priv); + batadv_tt_tvlv_container_update(bat_priv, &changes_list, + changes_num); return; } @@ -3782,7 +3817,7 @@ static void batadv_tt_local_commit_changes_nolock(struct batadv_priv *bat_priv) /* reset the sending counter */ atomic_set(&bat_priv->tt.ogm_append_cnt, BATADV_TT_OGM_APPEND_MAX); - batadv_tt_tvlv_container_update(bat_priv); + batadv_tt_tvlv_container_update(bat_priv, &changes_list, changes_num); } /** -- 2.53.0