{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-92508", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-16T12:21:13.872Z", "datePublished": "2026-09-17T16:10:19.443Z", "dateUpdated": "2026-10-19T09:04:14.344Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:04:14.344Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/core: Fix potential use after free in ib_free_cq()\n\nWhen accessing a CQ via the netlink path the only synchronization\nmechanism for the said CQ is rdma_restrack_get().\nCurrently, rdma_restrack_del() is invoked at the end of\nib_free_cq(), which is too late, since by that point\nvendor-specific resources associated with the CQ might already be\nfreed. This can leave a short window where the CQ remains accessible\nthrough restrack, leading to a potential use-after-free.\n\nFix this by moving the rdma_restrack_del() call to be before the freeing\nof the vendor-specific resources ensuring that the CQ is removed from\nrestrack before its internal resources are released.\nThis guarantees that no new users hold references to a CQ that is in\nthe process of destruction." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The use side is a local NETLINK_RDMA RDMA_NLDEV_CMD_RES_CQ_GET handled by nldev_res_get_cq_doit/dumpit → res_get_common_doit/dumpit, which rdma_restrack_get()s a CQ still in the xarray while ib_free_cq() is destroying it. No remote protocol message carries the lookup; the accessor is a netlink syscall.\nAC:L - The attacker drives both sides of the race: one thread loops RDMA_NLDEV_CMD_RES_CQ_GET while another opens and drops kernel-ULP RDMA connections so ib_free_cq() runs (svc_rdma_free() or smbdirect_connection_destroy_qp()). That is not a victim-only timing window.\nPR:L - RDMA_NLDEV_CMD_RES_CQ_GET in nldev_cb_table has no RDMA_NL_ADMIN_PERM, and NETLINK_RDMA is created with NL_CFG_F_NONROOT_RECV, so an ordinary user can dump CQs. Kernel CQ teardown via /dev/infiniband/rdma_cm (ucma_misc mode 0666) also does not need init-namespace root.\nUI:N - The attacker sends the RDMA_NLDEV_CMD_RES_CQ_GET dumps and tears down their own kernel-ULP RDMA connections; no other user must mount a volume, open a device, or confirm an action.\nS:U - The UAF is of host-kernel CQ vendor state (ib_cq buffers freed in destroy_cq/pre_destroy_cq) and stays inside the same kernel authority; it is not a VM escape, IOMMU bypass, or guest-to-host boundary cross.\nC:H - c4iw_destroy_cq() → destroy_cq() dma_free_coherent()s chp->cq.queue before rdma_restrack_del(); a concurrent fill_res_cq_entry → c4iw_fill_res_cq_entry still indexes that queue, so the UAF reads freed CQ-ring memory.\nI:H - The same ib_free_cq() window lets fill_res_cq_entry use vendor CQ resources already released by destroy_cq/pre_destroy_cq (Chelsio queue pages; mlx5 destroy_cq_kernel CQ buffers). Reclaiming that heap object yields an arbitrary write and control-flow hijack.\nA:H - fill_res_cq_entry walking a CQ whose queue or HW context was already freed in ib_free_cq() (after pre_destroy_cq/destroy_cq, before rdma_restrack_del) oopses or panics the kernel even without a crafted exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/cq.c" ], "versions": [ { "version": "43d781b9fa562f0c6e50f62c870fbfeb9dc85213", "lessThan": "a804b162f9bc2b38b2ed1b4752eea9faadb1645b", "status": "affected", "versionType": "git" }, { "version": "43d781b9fa562f0c6e50f62c870fbfeb9dc85213", "lessThan": "91f8a17a22ab615a03743120e19935e731f28fb9", "status": "affected", "versionType": "git" }, { "version": "43d781b9fa562f0c6e50f62c870fbfeb9dc85213", "lessThan": "76f2cb4f721815c3b6262a6dc2151de88646924c", "status": "affected", "versionType": "git" }, { "version": "43d781b9fa562f0c6e50f62c870fbfeb9dc85213", "lessThan": "b8dcca427096fc9c50f1b376847fea72bc842d31", "status": "affected", "versionType": "git" }, { "version": "43d781b9fa562f0c6e50f62c870fbfeb9dc85213", "lessThan": "9abea37942534eeb049335476178696b654b000c", "status": "affected", "versionType": "git" }, { "version": "43d781b9fa562f0c6e50f62c870fbfeb9dc85213", "lessThan": "43403fe45379c64fa6276e5a8ede44493e5d2d3d", "status": "affected", "versionType": "git" }, { "version": "43d781b9fa562f0c6e50f62c870fbfeb9dc85213", "lessThan": "29dc2f8e1c97372c2871a70088707933515fbd5b", "status": "affected", "versionType": "git" }, { "version": "7ac277a01f9017fcde4f3f81670c995992945433", "status": "affected", "versionType": "git" }, { "version": "093f87dda065e0f618dd577985eccbe85efb9b54", "status": "affected", "versionType": "git" }, { "version": "5.8.17", "lessThan": "5.9", "status": "affected", "versionType": "semver" }, { "version": "5.9.2", "lessThan": "5.10", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/cq.c" ], "versions": [ { "version": "5.10", "status": "affected" }, { "version": "0", "lessThan": "5.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "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": "5.10", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a804b162f9bc2b38b2ed1b4752eea9faadb1645b" }, { "url": "https://git.kernel.org/stable/c/91f8a17a22ab615a03743120e19935e731f28fb9" }, { "url": "https://git.kernel.org/stable/c/76f2cb4f721815c3b6262a6dc2151de88646924c" }, { "url": "https://git.kernel.org/stable/c/b8dcca427096fc9c50f1b376847fea72bc842d31" }, { "url": "https://git.kernel.org/stable/c/9abea37942534eeb049335476178696b654b000c" }, { "url": "https://git.kernel.org/stable/c/43403fe45379c64fa6276e5a8ede44493e5d2d3d" }, { "url": "https://git.kernel.org/stable/c/29dc2f8e1c97372c2871a70088707933515fbd5b" } ], "title": "RDMA/core: Fix potential use after free in ib_free_cq()", "x_generator": { "engine": "bippy-1.2.0" } } } }