{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-93224", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-17T16:02:15.094Z", "datePublished": "2026-09-24T15:21:10.542Z", "dateUpdated": "2026-10-19T09:07:35.798Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:07:35.798Z" }, "descriptions": [ { "lang": "en", "value": "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, &newxprt->sc_rn) unconditionally.\nsvcxprt_rdma is kzalloc'd, 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's slot 0 and performs an unmatched kref_put() on the\nrpcrdma_device's 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 -> 2 -> 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->rn_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 ->xpo_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()'s non-listener call\nto rpcrdma_rn_unregister() for transports whose register attempt\nfailed or never ran." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - svcrdma is nfsd's RPC-over-RDMA server; a remote peer over routable RoCEv2 or iWARP sends RDMA_CM CONNECT_REQUEST to svc_rdma_listen_handler/handle_connect_req, which queues newxprt so svc_handle_xprt calls svc_rdma_accept, whose errout invokes the unguarded rpcrdma_rn_unregister.\nAC:H - The unmatched rpcrdma_rn_unregister in svc_rdma_accept errout runs only if rpcrdma_rn_register failed (RPCRDMA_RD_F_REMOVING or xa_alloc ENOMEM); a remote peer can send CONNECT_REQUEST but cannot unbind the IB device or force that GFP_KERNEL failure, and the UAF needs that in-progress rpcrdma_remove_one.\nPR:N - RDMA_CM CONNECT_REQUEST handling in svc_rdma_listen_handler, handle_connect_req, and svc_rdma_accept runs before svc_process/svc_authenticate; the CM handshake has no RPC or NFS credential check, so an unauthenticated peer can drive the failed-accept errout.\nUI:N - Sending CONNECT_REQUEST to an NFS/RDMA listener already created via nfsd portlist is enough to reach svc_rdma_accept; racing ib_unregister_device is attack complexity, not a victim mount, click, or other user action.\nS:U - The wrong-slot rd_xa erase, unmatched rd_kref put, and any use-after-free of rpcrdma_device or the victim svcxprt_rdma's IB objects stay in the host kernel that runs nfsd/svcrdma; this is not a VM, IOMMU, or sandbox escape.\nC:H - On pre-register errout, rpcrdma_rn_unregister xa_erase()s rd_xa index 0 (kzalloc'd sc_rn.rn_index) of another transport and kref_put()s rd_kref while rpcrdma_remove_one may walk the same xarray; that transport's sc_cm_id/QP and the kfree'd rpcrdma_device become reclaimable slab UAF reads.\nI:H - The extra kref_put can make rpcrdma_remove_one's refcount_dec_and_test skip wait_for_completion and kfree(rd) while a live transport later xa_erase/kref_put or QP/CM ops write through the freed rpcrdma_device or un-notified IB objects, a UAF write primitive.\nA:H - A concurrent rpcrdma_remove_one that proceeds after the unmatched kref_put, or later QP/CM use of a transport whose slot-0 notification was erased, dereferences freed IB or rpcrdma_device memory and oopses or panics; any UAF is availability High per kernel CVSS guidance." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/xprtrdma/ib_client.c", "net/sunrpc/xprtrdma/svc_rdma_transport.c" ], "versions": [ { "version": "cb3cba0ec372fa7c5f5f5c12990bef02e458ab86", "lessThan": "0335800071a6dfdf7d21d729b5e7d8fa98936211", "status": "affected", "versionType": "git" }, { "version": "8ac6fcae5dc0e801f1c82a83f5ae2c0a4db19932", "lessThan": "5aabe070c00e5bdf4ab150fb5f72ad5f266d6241", "status": "affected", "versionType": "git" }, { "version": "8ac6fcae5dc0e801f1c82a83f5ae2c0a4db19932", "lessThan": "45a444a17240f4fa2235f0dfd4a96fc80f1eb2c2", "status": "affected", "versionType": "git" }, { "version": "8ac6fcae5dc0e801f1c82a83f5ae2c0a4db19932", "lessThan": "26190394c64c9429481fc88a4738f70bb92fb352", "status": "affected", "versionType": "git" }, { "version": "d310955106c358c8e1ea682defd8e21af44a6cba", "status": "affected", "versionType": "git" }, { "version": "6.12.35", "lessThan": "6.12.109", "status": "affected", "versionType": "semver" }, { "version": "6.15.4", "lessThan": "6.16", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/xprtrdma/ib_client.c", "net/sunrpc/xprtrdma/svc_rdma_transport.c" ], "versions": [ { "version": "6.16", "status": "affected" }, { "version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.35", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0335800071a6dfdf7d21d729b5e7d8fa98936211" }, { "url": "https://git.kernel.org/stable/c/5aabe070c00e5bdf4ab150fb5f72ad5f266d6241" }, { "url": "https://git.kernel.org/stable/c/45a444a17240f4fa2235f0dfd4a96fc80f1eb2c2" }, { "url": "https://git.kernel.org/stable/c/26190394c64c9429481fc88a4738f70bb92fb352" } ], "title": "svcrdma: Fix unmatched rn_unregister on failed accept", "x_generator": { "engine": "bippy-1.2.0" } } } }