CVE-2026-74434

Technical Description

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

rxrpc: Don't move a peeked OOB message onto the pending queue

rxrpc_recvmsg_oob() takes a received oob message off recvmsg_oobq and,

if a response is needed, moves it onto the pending_oobq tree. However,

only the unlink from recvmsg_oobq is guarded by MSG_PEEK; the move onto

pending_oobq always runs.

As a result, reading a challenge with MSG_PEEK leaves the skb on

recvmsg_oobq while also adding it to pending_oobq. Since struct

sk_buff's rbnode shares storage with its next and prev pointers,

rb_insert_color() overwrites the list linkage, and the skb, which holds

a single reference, becomes reachable from both queues at once.

When the socket is closed both queues are drained in turn. While

draining recvmsg_oobq, __skb_unlink() follows the next and prev

pointers that rbnode has overwritten and writes to a bad address. Also,

as the skb holds a single reference but is freed from each queue, both

the skb and the connecti

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