Re: [PATCH net] netlink: reset skb headers before unicast and multicast filtering

Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni [off-list ref]:

On Tue,  6 Oct 2026 15:42:32 -0700 you wrote:

Socket filters can use SKF_NET_OFF and SKF_LL_OFF to read relative to
an skb's network and MAC headers. Netlink producers may reserve
headroom without resetting those headers, allowing a receiving socket's
filter to read data before the initialized message.

For example, IWPM HELLO replies are allocated with dev_alloc_skb(),
which reserves NET_SKB_PAD bytes. An unprivileged NETLINK_RDMA user can
attach a classic socket filter and disclose this headroom through the
length of the delivered reply. The resets in netlink_dump() do not help
because IWPM sends a separately allocated skb through netlink_unicast().

[...]

Here is the summary with links:
  - [net] netlink: reset skb headers before unicast and multicast filtering
    https://git.kernel.org/netdev/net/c/8bf659bd54e1

You are awesome, thank you!
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