From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f199.google.com (mail-qt1-f199.google.com [209.85.160.199]) (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 68003314A60 for ; Fri, 11 Sep 2026 06:22:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789107725; cv=none; b=q/ySt3/2WGxuL6vQzav/Vpoh1gqe2U3HPlGwepBwZrTgrsdl5C4THh3Hj5dcSNEzostJh40gz4gnvJh1Hwq8Y9hrKevF14cfTBDnwgw/qhwgTSpOnaOdoyz+2/f99QmHKvKswVMcLfBlIesBH9HBkeic9RAQlGxi9hMq3QXAO4I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789107725; c=relaxed/simple; bh=AbNgaPMxIwnYwU8R3P3SlUdu6bfOBnjKzjfHijZrP9k=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=npWbah+CeC78I2yDnv29DOEU/A+xSLkXxJ0MeRtJhllggvSftlJRdrrMIv9lpoSUMLFGrp1AsIHIfu/5rNMnWoH+wz6LGIH7+idELXt50hvOPDyIli4kDV8QxNuVz2tP2GUQbFFaqyyRnmGZVOhy2lJI9qAOGg11d4e1Oz2AuLk= 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=W/w6CecX; arc=none smtp.client-ip=209.85.160.199 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="W/w6CecX" Received: by mail-qt1-f199.google.com with SMTP id d75a77b69052e-53094ff7090so14327311cf.1 for ; Thu, 10 Sep 2026 23:22:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1789107723; x=1789712523; 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=C+pHE0n2DorAuOr5FcGLKW27gjwiTwQ8LXlNVlFLmKo=; b=W/w6CecXafK7wDNe9aAZg8tyQZAQIhK9DUzJg/jQj7nBG7xvM7rVbyvJpIuYEkc4M7 aTgmPbgT2iuAxD9JqQxg3DBJRSOWBhmLKq2GvEXP8ydEgGf26acxj+OTIV4xfSzraUQq YTT+eyvBqYFTz4HsoGSg1oodOAzcIxa02T4rG/1ja6aqKA5G5yrH63tEynp6yl8Ne9hC jrW/5HB1SM5FPPO3oGgG8Nakjj50LGMlGehukyKSdPmDiPzLFZB5CbRSRxkFsFbpB07h i6HT0NWgu2u8ldZeWywum2IfwyP4Nd6mABXJ7t5u57Pmw1bOCU9Zs3Y6e5mlJZMPYc7Z 4A/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789107723; x=1789712523; 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=C+pHE0n2DorAuOr5FcGLKW27gjwiTwQ8LXlNVlFLmKo=; b=EoKVjTSpS52ut8fflTywuTanXKFNCBp1GbeoD3aFTVGmwFmTKlBKw62LIK67WSAHGd 7gjOvVNojcIZZJ4d5PwDn8ADkiA4f3EIaU7sLKU6CO86bdzOJ9/BDAys2SmCkAcFXhdX Pjgyg4e1rULE27xuM389HFG2Yv+a1evae5Vyli/NvmiN7/n6BEMVfouavEXJbLR6GDL+ mNDMJVDz/P9BDJUQsEX0EaIYP5g1+RYXhDB9CdeAuIYTKUXlPQ3/JBh3JfZmC6Yh8VLE BpXZjwmJpVbqmJT4l0H7F59Z5nbzWc6RTbZ4tqakWtJV4nhYlgmhWZZLk34lXKZywujL Azkg== X-Forwarded-Encrypted: i=1; AKwUvBwjwHUumpVYtCmcUH4AbZhiv0UHr8KbDWuZvLawDFge9d0bI/8HwZNJ67w40SpHAPdc9BIJo1Q=@vger.kernel.org X-Gm-Message-State: AFuF++k1jvPbmON9/5N6R1xGpIWNJC0qBigUPdi4tCkYtObbExwSNby1 FPaP7JBrrvp3a/KxdtH+213TGdBNvkOjtfz8snd23tRYiih8VgbER9Bne9ebnrNqszShZX/sVR/ JdOKM0DsM77vxZQ== X-Received: from qvuy10.prod.google.com ([2002:ad4:45aa:0:b0:912:2b3:82c3]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:622a:8c1b:b0:530:d3d2:f8b0 with SMTP id d75a77b69052e-530d3d306aemr7124711cf.24.1789107723106; Thu, 10 Sep 2026 23:22:03 -0700 (PDT) Date: Fri, 11 Sep 2026 06:21:55 +0000 In-Reply-To: <20260911062200.231316-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260911062200.231316-1-edumazet@google.com> X-Mailer: git-send-email 2.55.0.1007.g17ff1f9808-goog Message-ID: <20260911062200.231316-2-edumazet@google.com> Subject: [PATCH v3 net-next 1/6] 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 , Ido Schimmel , Andrew Lunn , 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 dd94085e088656d27b62420a5c8c95c609510a4c..0a18c32902da08dc2732e2aea10d58b8753fe57f 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); -- 2.55.0.1007.g17ff1f9808-goog