CVE-2026-74611

/// Technical description

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

tls: rx: restore msg_iter before TLS 1.3 optimistic retry

tls_decrypt_sg() advances msg->msg_iter when it maps user pages for

the optimistic TLS 1.3 zero-copy path. If the decrypted record turns

out not to be unpadded application data, tls_decrypt_sw() retries into

a kernel skb, but leaves the iterator advanced.

The subsequent copy from the skb then writes decrypted bytes again at

a later point in the caller iovecs while recvmsg() reports only the

post-retry length. A TLS peer can trigger this after the receiver

enables TLS_RX_EXPECT_NO_PAD.

Revert the iterator by the number of bytes consumed by the optimistic

mapping before retrying without zero-copy.

Add a selftest which sends a TLS 1.3 control record with

TLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not

overwrite later iovecs beyond the returned length.

/// 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