GHSA-G4HJ-W3XR-5RR3
Vulnerability from github – Published: 2026-09-24 18:31 – Updated: 2026-09-25 06:30In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Fix unmatched rn_unregister on failed accept
When svc_rdma_accept() takes the errout path before rpcrdma_rn_register() has succeeded, the existing cleanup block calls rpcrdma_rn_unregister(dev, &newxprt->sc_rn) unconditionally. svcxprt_rdma is kzalloc'd, so on that path sc_rn.rn_index is 0 and sc_rn.rn_done is NULL; the unregister therefore xa_erase()s another caller's slot 0 and performs an unmatched kref_put() on the rpcrdma_device's rd_kref.
The same errout also brackets the cleanup with svc_xprt_get()/ svc_xprt_put() around the kref_init() birth reference. The kref goes 1 -> 2 -> 1 and never reaches 0, so the svcxprt_rdma (and the net/ns_tracker it pinned) is leaked on every failed accept.
rpcrdma_rn_register() writes rn->rn_done last, only after xa_alloc() and kref_get() have both succeeded, so rn_done == NULL is a natural "never registered" sentinel. Guard rpcrdma_rn_unregister() with an early return when rn_done is NULL, and clear rn_done before the matching xa_erase() so a repeated unregister is also a no-op.
With that guard in place, the accept errout drops the kref_init() birth reference via svc_xprt_put(), which dispatches svc_rdma_free(). Teardown of sc_qp, sc_sq_cq, sc_rq_cq, and sc_pd runs under existing IS_ERR/NULL guards in svc_rdma_free(); sc_rn is covered by the new rn_done sentinel; sc_cm_id is non-NULL on every errout path because svc_rdma_accept() dereferences it above the first goto errout.
svc_xprt_free() drops the module reference associated with the freed transport, and svc_handle_xprt() drops its pre-acquired reference when ->xpo_accept() returns NULL. Take a replacement module reference before svc_xprt_put() so the two module_put()s remain balanced.
The rn_done guard also covers svc_rdma_free()'s non-listener call to rpcrdma_rn_unregister() for transports whose register attempt failed or never ran.
{
"affected": [],
"aliases": [
"CVE-2026-93224"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-24T16:17:17Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Fix unmatched rn_unregister on failed accept\n\nWhen svc_rdma_accept() takes the errout path before\nrpcrdma_rn_register() has succeeded, the existing cleanup block\ncalls rpcrdma_rn_unregister(dev, \u0026newxprt-\u003esc_rn) unconditionally.\nsvcxprt_rdma is kzalloc\u0027d, so on that path sc_rn.rn_index is 0 and\nsc_rn.rn_done is NULL; the unregister therefore xa_erase()s another\ncaller\u0027s slot 0 and performs an unmatched kref_put() on the\nrpcrdma_device\u0027s rd_kref.\n\nThe same errout also brackets the cleanup with svc_xprt_get()/\nsvc_xprt_put() around the kref_init() birth reference. The kref\ngoes 1 -\u003e 2 -\u003e 1 and never reaches 0, so the svcxprt_rdma (and the\nnet/ns_tracker it pinned) is leaked on every failed accept.\n\nrpcrdma_rn_register() writes rn-\u003ern_done last, only after xa_alloc()\nand kref_get() have both succeeded, so rn_done == NULL is a natural\n\"never registered\" sentinel. Guard rpcrdma_rn_unregister() with an\nearly return when rn_done is NULL, and clear rn_done before the\nmatching xa_erase() so a repeated unregister is also a no-op.\n\nWith that guard in place, the accept errout drops the kref_init()\nbirth reference via svc_xprt_put(), which dispatches svc_rdma_free().\nTeardown of sc_qp, sc_sq_cq, sc_rq_cq, and sc_pd runs under existing\nIS_ERR/NULL guards in svc_rdma_free(); sc_rn is covered by the new\nrn_done sentinel; sc_cm_id is non-NULL on every errout path because\nsvc_rdma_accept() dereferences it above the first goto errout.\n\nsvc_xprt_free() drops the module reference associated with the freed\ntransport, and svc_handle_xprt() drops its pre-acquired reference\nwhen -\u003expo_accept() returns NULL. Take a replacement module reference\nbefore svc_xprt_put() so the two module_put()s remain balanced.\n\nThe rn_done guard also covers svc_rdma_free()\u0027s non-listener call\nto rpcrdma_rn_unregister() for transports whose register attempt\nfailed or never ran.",
"id": "GHSA-g4hj-w3xr-5rr3",
"modified": "2026-09-25T06:30:27Z",
"published": "2026-09-24T18:31:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93224"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0335800071a6dfdf7d21d729b5e7d8fa98936211"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/26190394c64c9429481fc88a4738f70bb92fb352"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/45a444a17240f4fa2235f0dfd4a96fc80f1eb2c2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5aabe070c00e5bdf4ab150fb5f72ad5f266d6241"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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