From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE09347F3C3 for ; Tue, 22 Sep 2026 18:11:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790100670; cv=none; b=KcFD4skOGXLXOSYbBwRz+9Ay/D8ng+/Mci5OPtO2sYpTMXTs5kpTtazGoe9B9gKVhFchiY2rOoxh9MsO1U7zVhd9IJ7NOhG/hWA3Drk3Np0A4ue7SYaQZFBSXqmjrbSpt4i17ktjnTr6LDa06Mu+lWBcKKQUGH9dstYkmcavC2c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790100670; c=relaxed/simple; bh=TaFb4eSuakn16y/HCqbul6dLc6ai2mslQenZjmXED9g=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=aA9yJcQyznK9mEH8YQOIDoMXcXDq0fgcDLmywiY3huDcQRk05qWGXmxaa7zUOQfrbUvz/daKuJNCQ+izM/dmVCv8BcrKUbCZQyuCpi+FECPCUVpNZIFgWd0L5Ky1QZKWwgYUbwy8Q+oZwCGUIo4OotOlAj6ObfOgItra1d5O0dw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=hjKZ8Tvo; arc=none smtp.client-ip=209.85.160.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hjKZ8Tvo" Received: by mail-qt1-f197.google.com with SMTP id d75a77b69052e-53124d6a362so3641161cf.0 for ; Tue, 22 Sep 2026 11:11:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790100667; x=1790705467; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=akNW2gA1xqJv9Y2CV3ju1rGNtJUn9j9S8EFGtBjOoUo=; b=hjKZ8TvoYFYmU8tGaUPWP3qQUOGp/6ibEtMrVfZzKGBerIr/OEa51vcHHYJGp4xuKH MCTW1Cjxjv97M+zlljSqXbruUQixdskBH96xqVZYxHtBWfPNwRuauUvW4eBlJuE6R3qZ 5bqvtA3IpOvZi2qyXa9ZHvq3sYnV9vFMeCFxtl24RzGMlcei33+kKj57d4Z+5AWxxgBA OPQD9Ei3YwsOk0QaEYNQHsZU1q4oL/Umc+JOWYWGnpbJW5o7h0/vtyYUREwURDg6aITV qF7u15fuUsKtfzVr8XJsJC9BDP3nZR30EuILwmLf7Wk2OtoH2gD1jPrgH51kTo+6WGND sRnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790100667; x=1790705467; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=akNW2gA1xqJv9Y2CV3ju1rGNtJUn9j9S8EFGtBjOoUo=; b=EOSeNbw8KdOIoRJq79QGWpOM3ANmwzSNEjU17qnQViUhbbQEU9p6lLe/kpnhQ/D0D8 5ZaYzZEVJwMbvUmkuPTQdZjTGA67HoGKsGY3QM8EhgCVqZFoK3GlgBgr+IsLO72mWMQj 71hB/AyP2i8uRbeWZB9ZQ/iC7XKNAd/281zXTo1e2ZAT7whL+NLFwCbJGlMvO1HwqYOq Gv7M6nf14ZnLbHIpPb5rQRd3vVkcmKyKFXPt0T/IZ4JIL09kaLvsgBrIj8lwEiR8V6SG cWMSdfhJUrp200PTq54pZGh+jAfte2o5WQXDEYhmhL84zMuAv7rtfVPdOL5Opm+zgUtF MSTg== X-Forwarded-Encrypted: i=1; AKwUvBwiy3IeIxtlQbEhvW/NlAhmTxjmlFjdHf6rgArOMsfy01AwbY8HYlw9vR1AlTml2U/K4BlGX9w=@vger.kernel.org X-Gm-Message-State: AFuF++ngiImxW4eToEFy9V0aYDCMeM70MWagkKGhZC9PP1q6hx0lU43j a+TKQeQX1Q91yTPTVFhMbaFJvjCKkqT+vwFGAd6D5K8b3nXoYxF9xhX19jmKfN/gqrlx/MZAZAE chOg2EocV+sIorw== X-Received: from qtbkf15.prod.google.com ([2002:a05:622a:2a8f:b0:532:b81b:a13]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:622a:4117:b0:532:8ed7:534 with SMTP id d75a77b69052e-532eadcbef3mr5345101cf.37.1790100667301; Tue, 22 Sep 2026 11:11:07 -0700 (PDT) Date: Tue, 22 Sep 2026 18:10:56 +0000 In-Reply-To: <20260922181102.3989489-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260922181102.3989489-1-edumazet@google.com> X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog Message-ID: <20260922181102.3989489-3-edumazet@google.com> Subject: [PATCH v6 net-next 2/8] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Kuniyuki Iwashima , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" RTM_GETTUNNEL dumps currently run under RTNL lock, but vxlan_vnifilter_dump() also acquires rcu_read_lock(). 1) Currently vxlan_vnifilter_dump_dev() traverses vg->vni_list using list_for_each_entry_safe(). Even though RTNL is held today, writers modify vg->vni_list with list_add_rcu() and list_del_rcu(). Switch to list_for_each_entry_rcu() for proper RCU traversal and as preparation for future lockless dump support. 2) During a paginated dump, RTNL is released between dump skbs. If vxlan_vnifilter_dump_dev() returns early because VXLAN_F_VNIFILTER is not set or vg has no VNIs, cb->args[1] was not cleared. This leaked a non-zero VNI offset to subsequent devices, silently skipping their first N VNIs. Furthermore, if devices are added or removed between dump calls, ordinal device indexes can shift. Track the current device ifindex in cb->args[2] and reset cb->args[1] if the device changes. Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima --- drivers/net/vxlan/vxlan_vnifilter.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c index 336e8128be480a544caf0115bfb5b9254fe12eb3..0a04e8875f7dc4da66a01de8d0e99f82c75c1fdd 100644 --- a/drivers/net/vxlan/vxlan_vnifilter.c +++ b/drivers/net/vxlan/vxlan_vnifilter.c @@ -333,22 +333,34 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev, struct sk_buff *skb, struct netlink_callback *cb) { - struct vxlan_vni_node *tmp, *v, *vbegin = NULL, *vend = NULL; + struct vxlan_vni_node *v, *vbegin = NULL, *vend = NULL; struct vxlan_dev *vxlan = netdev_priv(dev); struct tunnel_msg *new_tmsg, *tmsg; - int idx = 0, s_idx = cb->args[1]; struct vxlan_vni_group *vg; struct nlmsghdr *nlh; + int idx = 0, s_idx; bool dump_stats; int err = 0; - if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER)) + if (cb->args[2] != dev->ifindex) { + cb->args[1] = 0; + cb->args[2] = dev->ifindex; + } + s_idx = cb->args[1]; + + if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER)) { + cb->args[1] = 0; + cb->args[2] = 0; return -EINVAL; + } /* RCU needed because of the vni locking rules (rcu || rtnl) */ vg = rcu_dereference(vxlan->vnigrp); - if (!vg || !vg->num_vnis) + if (!vg || !vg->num_vnis) { + cb->args[1] = 0; + cb->args[2] = 0; return 0; + } tmsg = nlmsg_data(cb->nlh); dump_stats = !!(tmsg->flags & TUNNEL_MSG_FLAG_STATS); @@ -362,7 +374,7 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev, new_tmsg->family = PF_BRIDGE; new_tmsg->ifindex = dev->ifindex; - list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) { + list_for_each_entry_rcu(v, &vg->vni_list, vlist) { if (idx < s_idx) { idx++; continue; @@ -394,6 +406,7 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev, } cb->args[1] = err ? idx : 0; + cb->args[2] = err ? dev->ifindex : 0; nlmsg_end(skb, nlh); -- 2.55.0.1082.g2b9226bbc0-goog