GHSA-86FH-QJ8H-2FHQ
Vulnerability from github – Published: 2026-09-17 18:32 – Updated: 2026-09-17 18:32In 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.
{
"affected": [],
"aliases": [
"CVE-2026-93107"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-17T17:18:05Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Avoid reprocessing the current packet after the QP enters the error state\n\nWhen do_complete() finds the QP in the error state it returns\nRESPST_CHK_RESOURCE. Before commit 49dc9c1f0c7e (\"RDMA/rxe: Cleanup\nreset state handling in rxe_resp.c\") this was the flush loop:\ncheck_resource() had an error-state branch that fetched each remaining\nrecv WQE and completed it with IB_WC_WR_FLUSH_ERR, without touching\nthe current packet. That commit removed the error-state branch from\ncheck_resource() (draining is now done at rxe_receiver() entry) but\nkept the do_complete() error-state return.\n\nAs a result, when a QP moves to the error state while a packet is\nbeing completed - e.g. an rdma_cm disconnect racing with receive\nprocessing - the responder state machine loops back into the request\nprocessing chain with the already-completed packet still in hand:\ncheck_resource() fetches a fresh recv WQE, execute()/send_data_in()\ncopies the same packet payload again, do_complete() posts another\nIB_WC_SUCCESS CQE (qp-\u003eresp.status is still 0), and control returns\nto the error-state check. The loop re-executes the same packet once\nper posted recv WQE (observed: ~1000 duplicate IB_WC_SUCCESS\ncompletions of one SEND, one per ~8us, matching the RQ occupancy)\nuntil the RQ is exhausted, after which qp-\u003eresp.wqe is NULL and\nsend_data_in() dereferences it:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000014\n Workqueue: rxe_wq do_work\n RIP: copy_data+0x29/0x1f0\n Call Trace:\n send_data_in+0x25/0x50\n rxe_receiver+0xf36/0x1dd0\n\nThe duplicate completions are indistinguishable from real receives to\nthe ULP. During an rds stress test, the message was accepted as new and\ndelivered the same datagram to user space hundreds of times, corrupting\nthe stream; any ULP that relies on RC exactly-once delivery is affected.\n\nA live packet reaching the error-state check in do_complete() has\nbeen executed and completed exactly once and must be consumed, not\nre-processed. Return RESPST_CLEANUP for it (dequeue and free); keep\nreturning RESPST_CHK_RESOURCE for the pkt == NULL case.",
"id": "GHSA-86fh-qj8h-2fhq",
"modified": "2026-09-17T18:32:10Z",
"published": "2026-09-17T18:32:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93107"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0d37e2503efd1069a74be740eadf63ea17c96810"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/15ae32c4a3551c4c9da457370bdfdd65d171e512"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/399713f1f0eac641351c8ceaec0ab8244ddcf78c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/62a4b48767e06fdd64548450fae2b1ffc6ff5d69"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c319b986a88cedf600c4497cd7814a891b2f9e7c"
}
],
"schema_version": "1.4.0",
"severity": []
}
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