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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | RDMA/rxe: Avoid reprocessing the current packet after the QP enters the error state | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:11:17.791Z
Reserved: 2026-09-17T16:02:15.085Z
Link: CVE-2026-93107
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:18:05.060
Modified: 2026-09-17T17:18:05.060
Link: CVE-2026-93107
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.