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 9EA5B33F38B; Fri, 21 Nov 2025 13:52:03 +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=1763733123; cv=none; b=ZeSxVYdq7GJcYM/3eE+yL57tWqwer2clAHhYwwpXxJYNJgl+BkEzcFEBpX2S9DDIA5uuEaWOqKMyI2vmI6GgVAWW1l8TZS120RcGI1fsn5iGVYKa8nnuiH2y31tQLp1X3LhmuLY0km+bcJAQku/rh4wL4AyGf6ITm46m/GzNvtI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763733123; c=relaxed/simple; bh=7x1/uABPiExD0VmIfPNdgdXLEajF9YsbKf8kWZsoJCE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mJqrF2L14PxObPOBRubnC3HFAaqBdfjqFDb8qraTCu/a0dhprh31tfvadtG4JnH2nORAKSdDvTnn+noVcaKgpraS+RDoSPmqhRj9C0MgPtrwApy15h0poBCV188O+U1/ig8gEl8iw6bKHXks4gNFlA9hCmJp/jizHNUxnk0WOLM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Mh7ojJ8x; 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="Mh7ojJ8x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26C91C4CEF1; Fri, 21 Nov 2025 13:52:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763733123; bh=7x1/uABPiExD0VmIfPNdgdXLEajF9YsbKf8kWZsoJCE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mh7ojJ8xYe7/kgod4CnlYow4pWCuK0lC+ksKZ+FZd46mg5ujEM0MWUOTdsVgiAmUz vFgNsjZZwhQ0pZBbBI6Icpwb/tcR7AqsSdcQhHZzjY18nbn9YXBT4QyGjT1OmdHK5v /Qj3tJ2mIoRCrzr6vCFZ9vW31sc6ZcMjQEhpkhhw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ido Schimmel , Nikolay Aleksandrov , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 360/529] net: bridge: fix MST static key usage Date: Fri, 21 Nov 2025 14:10:59 +0100 Message-ID: <20251121130243.836862601@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130230.985163914@linuxfoundation.org> References: <20251121130230.985163914@linuxfoundation.org> User-Agent: quilt/0.69 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikolay Aleksandrov [ Upstream commit ee87c63f9b2a418f698d79c2991347e31a7d2c27 ] As Ido pointed out, the static key usage in MST is buggy and should use inc/dec instead of enable/disable because we can have multiple bridges with MST enabled which means a single bridge can disable MST for all. Use static_branch_inc/dec to avoid that. When destroying a bridge decrement the key if MST was enabled. Fixes: ec7328b59176 ("net: bridge: mst: Multiple Spanning Tree (MST) mode") Reported-by: Ido Schimmel Closes: https://lore.kernel.org/netdev/20251104120313.1306566-1-razor@blackwall.org/T/#m6888d87658f94ed1725433940f4f4ebb00b5a68b Signed-off-by: Nikolay Aleksandrov Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20251105111919.1499702-3-razor@blackwall.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/bridge/br_if.c | 1 + net/bridge/br_mst.c | 10 ++++++++-- net/bridge/br_private.h | 5 +++++ 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index 2450690f98cfa..6ffc81eedf074 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -386,6 +386,7 @@ void br_dev_delete(struct net_device *dev, struct list_head *head) del_nbp(p); } + br_mst_uninit(br); br_recalculate_neigh_suppress_enabled(br); br_fdb_delete_by_port(br, NULL, 0, 1); diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c index 3f24b4ee49c27..43a300ae6bfaf 100644 --- a/net/bridge/br_mst.c +++ b/net/bridge/br_mst.c @@ -22,6 +22,12 @@ bool br_mst_enabled(const struct net_device *dev) } EXPORT_SYMBOL_GPL(br_mst_enabled); +void br_mst_uninit(struct net_bridge *br) +{ + if (br_opt_get(br, BROPT_MST_ENABLED)) + static_branch_dec(&br_mst_used); +} + int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids) { const struct net_bridge_vlan_group *vg; @@ -225,9 +231,9 @@ int br_mst_set_enabled(struct net_bridge *br, bool on, return err; if (on) - static_branch_enable(&br_mst_used); + static_branch_inc(&br_mst_used); else - static_branch_disable(&br_mst_used); + static_branch_dec(&br_mst_used); br_opt_toggle(br, BROPT_MST_ENABLED, on); return 0; diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 798960ef2dcd0..c8a4e3b39b0e2 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -1899,6 +1899,7 @@ int br_mst_fill_info(struct sk_buff *skb, const struct net_bridge_vlan_group *vg); int br_mst_process(struct net_bridge_port *p, const struct nlattr *mst_attr, struct netlink_ext_ack *extack); +void br_mst_uninit(struct net_bridge *br); #else static inline bool br_mst_is_enabled(const struct net_bridge_port *p) { @@ -1934,6 +1935,10 @@ static inline int br_mst_process(struct net_bridge_port *p, { return -EOPNOTSUPP; } + +static inline void br_mst_uninit(struct net_bridge *br) +{ +} #endif struct nf_br_ops { -- 2.51.0