Re: [PATCH net] sctp: fix missing encap_port propagation for GSO fragments

Marcelo Ricardo Leitner <[email protected]> Mon, 13 Apr 2026 09:37:10 -0300
Newsgroups org.kernel.vger.linux-sctp,org.kernel.vger.netdev
Message-ID <[email protected]>
On Sun, Apr 12, 2026 at 02:13:51PM -0400, Xin Long wrote:
> encap_port in SCTP_INPUT_CB(skb) is used by sctp_vtag_verify() for
> SCTP-over-UDP processing. In the GSO case, it is only set on the head
> skb, while fragment skbs leave it 0.
> 
> This results in fragment skbs seeing encap_port == 0, breaking
> SCTP-over-UDP connections.
> 
> Fix it by propagating encap_port from the head skb cb when initializing
> fragment skbs in sctp_inq_pop().
> 
> Fixes: 046c052b475e ("sctp: enable udp tunneling socks")
> Signed-off-by: Xin Long <[email protected]>

Acked-by: Marcelo Ricardo Leitner <[email protected]>