CVE-2026-93105

/// Technical description

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

esp: do not unref managed frag pages in esp_ssg_unref()

esp_ssg_unref() releases the page references held on the source

scatterlist after the AEAD operation completes. It calls

skb_page_unref() on every frag page for an out-of-place transform

(req->src != req->dst), and in the error path of esp_output_tail()

(already_unref == true) on the request's own scatterlist.

This is wrong when the skb carries managed frags

(SKBFL_MANAGED_FRAG_REFS). Managed frags are owned by a zerocopy ubuf

and the skb does not hold a per-frag page reference; io_uring SEND_ZC

with a registered buffer attaches the bvec pages this way via

io_sg_from_iter(). The rest of the stack honours this invariant:

skb_release_data() skips the per-frag unref when SKBFL_MANAGED_FRAG_REFS

is set, and skb_zcopy_managed() is the guard used at the other unref

sites.

esp_ssg_unref() is missing that guard, so for a managed-frag skb it

drops a page reference t

/// 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