Re: [PATCH net] tun: free page on short-frame rejection in tun_xdp_one()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@xxxxxxxxxx>:

On Wed, 20 May 2026 09:00:21 -0700 you wrote:
> tun_xdp_one() returns -EINVAL on a frame shorter than ETH_HLEN without
> freeing the page that vhost_net_build_xdp() allocated for it.
> tun_sendmsg() discards that -EINVAL and still returns total_len, so
> vhost_tx_batch() takes the success path and never frees the page; each
> short frame in a batch leaks one page-frag chunk.
> 
> A local process that can open /dev/net/tun and /dev/vhost-net can hit
> this path: it attaches a tun/tap device as the vhost-net backend and
> feeds TX descriptors whose length minus the virtio-net header is below
> ETH_HLEN. Each kick leaks the page-frag chunks for that batch, and a
> tight submission loop exhausts host memory and triggers an OOM panic.
> Free the page before returning -EINVAL, matching the XDP-program error
> path in the same function.
> 
> [...]

Here is the summary with links:
  - [net] tun: free page on short-frame rejection in tun_xdp_one()
    https://git.kernel.org/netdev/net/c/f4feb1e20058

You are awesome, thank you!
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