{"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":"2026-09-25T05:09:45.728Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-25T05:09:45.728Z"},"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-rc1","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-rc1"},{"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"}}}}