CVE-2026-93107

Status: UPDATED  |  Advisory ID: CVE-2026-93107

Key Details

Affected Products, Subsystems & Sectors

What to Know

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

RDMA/rxe: Avoid reprocessing the current packet after the QP enters the error state

When do_complete() finds the QP in the error state it returns

RESPST_CHK_RESOURCE. Before commit 49dc9c1f0c7e ("RDMA/rxe: Cleanup

reset state handling in rxe_resp.c") this was the flush loop:

check_resource() had an error-state branch that fetched each remaining

recv WQE and completed it with IB_WC_WR_FLUSH_ERR, without touching

the current packet. That commit removed the error-state branch from

check_resource() (draining is now done at rxe_receiver() entry) but

kept the do_complete() error-state return.

As a result, when a QP moves to the error state while a packet is

being completed - e.g. an rdma_cm disconnect racing with receive

processing - the responder state machine loops back into the request

processing chain with the already-completed packet still in hand:

check_resource() fetches a fresh recv WQE, execute()/send_data_in()

copies the same packet payload again, do_complete() posts another

IB_WC_SUCCESS CQE (qp->resp.status is still 0), and control returns

to the error-state check. The loop re-executes the same packet once

per posted recv WQE (observed: ~1000 duplicate IB_WC_SUCCESS

completions of one SEND, one per ~8us, matching the RQ occupancy)

until the RQ is exhausted, after which qp->resp.wqe is NULL and

send_data_in() dereferences it:

BUG: kernel NULL pointer dereference, address: 0000000000000014

Workqueue: rxe_wq do_work

RIP: copy_data+0x29/0x1f0

Call Trace:

send_data_in+0x25/0x50

rxe_receiver+0xf36/0x1dd0

The duplicate completions are indistinguishable from real receives to

the ULP. During an rds stress test, the message was accepted as new and

delivered the same datagram to user space hundreds of times, corrupting

the stream; any ULP that relies on RC exactly-once delivery is affected.

A live packet reaching the error-state check in do_complete() has

been executed and completed exactly once and must be consumed, not

re-processed. Return RESPST_CLEANUP for it (dequeue and free); keep

returning RESPST_CHK_RESOURCE for the pkt == NULL case. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References