CVE-2026-93107
HighCVSS 8.2Exploitation Probability (EPSS)
Low risk45th percentile - higher than 45% of all known CVEs
Summary
A flaw in the Linux kernel RDMA/rxe module causes the same packet to be reprocessed after a QP enters the error state. When a QP transitions to error while a packet is being completed (e.g. an rdma_cm disconnect racing with receive processing), the responder state machine loops and repeatedly posts the same IB_WC_SUCCESS completion, eventually dereferencing a NULL pointer and panicking the kernel. The duplicate completions are indistinguishable from real receives, breaking RC exactly-once delivery.
Risk Assessment
The organization may experience a kernel panic (NULL pointer dereference) leading to system unavailability, as well as data stream corruption in RDMA-based applications that rely on exactly-once delivery. In stress tests a single message was delivered hundreds of times, potentially causing incorrect data and service failures.
Recommendation
Update the Linux kernel as soon as possible to a version containing the fix for CVE-2026-93107 (the RDMA/rxe corrective commit). Until the patch is deployed, consider limiting or monitoring RDMA workloads and verify whether the running kernel is affected.
Other vulnerabilities in Linux kernel RDMA/rxe
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

