Re: [PATCH] ethtool: tsinfo: release net_device reference in ethnl_tsinfo_start()
flat view
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-09-24 16:07:16
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Subsystem:
networking [ethtool], networking [general], the rest · Maintainers:
Andrew Lunn, Jakub Kicinski, "David S. Miller", Eric Dumazet, Paolo Abeni, Linus Torvalds
On Sat, 19 Sep 2026 20:48:03 +0000 Hui Peng wrote:
quoted hunk ↗ jump to hunk
- if (ctx->req_info->base.dev) { - struct net_device *dev = ctx->req_info->base.dev; + if (ctx->single_dev) { + struct net_device *dev = dev_get_by_index(net, ctx->pos_ifindex); + if (!dev) + return -ENODEV; netdev_lock_ops_compat(dev); ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb); netdev_unlock_ops_compat(dev); + dev_put(dev); return ret;
This issue gotta be theoretical, can you build a repro that actually triggers multi-skb dump for a single netdev? We don't have that much info, it's gonna fit. If you can trigger pls update the commit msg, if you can't let's instead make this "official" by adding:
diff --git a/net/ethtool/tsinfo.c b/net/ethtool/tsinfo.c
index c9b680a9cc3f..cbb5d6b7f3e3 100644
--- a/net/ethtool/tsinfo.c
+++ b/net/ethtool/tsinfo.c@@ -482,6 +482,7 @@ int ethnl_tsinfo_dumpit(struct sk_buff *skb, struct netlink_callback *cb) netdev_lock_ops_compat(dev); ret = ethnl_tsinfo_dump_one_net_topo(skb, dev, cb); netdev_unlock_ops_compat(dev); + /* We don't want to hold the device ref across messages */ + WARN_ON_ONCE(ret == -EMSGSIZE); return ret; }