CVE-2026-43500

Technical Description

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

rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present

The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE

handler in rxrpc_verify_response() copy the skb to a linear one before

calling into the security ops only when skb_cloned() is true. An skb

that is not cloned but still carries externally-owned paged fragments

(e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via

__ip_append_data, or a chained skb_has_frag_list()) falls through to

the in-place decryption path, which binds the frag pages directly into

the AEAD/skcipher SGL via skb_to_sgvec().

Extend the gate to also unshare when skb_has_frag_list() or

skb_has_shared_frag() is true. This catches the splice-loopback vector

and other externally-shared frag sources while preserving the

zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC

page_pool RX, GRO). The OOM/trace handling already in place is reused

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References