CVE-2026-98549

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

tcp: prevent collapsing skbs across boundary in rtx queue

tcp_write_collapse_fence() sets TCP_SKB_CB(skb)->eor = 1 on

tcp_write_queue_tail(sk) to prevent skbs queued after a switch to

device encryption from being collapsed into earlier skbs.

The fence is a no-op if all earlier data has already been transmitted

when the switch happens: sk->sk_write_queue is empty. The not yet

acknowledged earlier skbs wait in sk->tcp_rtx_queue with eor 0.

On a subsequent retransmit or SACK shift, tcp_retrans_try_collapse() or

tcp_shift_skb_data() can then merge an skb queued after the switch into

one queued before it.

Both users of the fence are affected:

- psp: devices only encrypt skbs with skb->decrypted set. The merged skb

keeps decrypted = 0 from the earlier skb, so merged data sent after

psp_sock_assoc_set_tx() is retransmitted in cleartext.

- tls device offload: the merged skb straddles the start marker set in

tls_se

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References