CVE-2026-64281

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64281", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.777Z", "datePublished": "2026-07-25T08:49:24.399Z", "dateUpdated": "2026-08-17T04:52:36.535Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:52:36.535Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: wake sq waiters when the transport closes\n\nThreads parked in svc_rdma_sq_wait() on sc_sq_ticket_wait or\nsc_send_wait can hang indefinitely in TASK_UNINTERRUPTIBLE state\nacross transport teardown, pinning svc_xprt references and\nblocking svc_rdma_free().\n\nThe close path sets XPT_CLOSE before invoking xpo_detach and both\nwait_event predicates include an XPT_CLOSE term, but the\npredicates are re-evaluated only on wakeup. sc_sq_ticket_wait has\nno completion-driven wake path; it is advanced solely by the\nchained ticket handoff inside svc_rdma_sq_wait() itself. Without\nan explicit wake at close, parked threads never observe\nXPT_CLOSE, hold their svc_xprt_get reference forever, and\nsvc_rdma_free() blocks on xpt_ref dropping to zero.\n\nTwo close entry points reach this transport. Local teardown runs\nsvc_rdma_detach() from svc_handle_xprt() -> svc_delete_xprt() ->\nxpo_detach() on a worker thread. A remote disconnect arrives at\nsvc_rdma_cma_handler(), which calls svc_xprt_deferred_close():\nthat sets XPT_CLOSE and enqueues the transport but does not\naccess either RDMA waitqueue, so a worker already parked in\nsvc_rdma_sq_wait() never re-evaluates its predicate. With every\nworker parked on this transport, no thread is available to run\nthe local teardown either, and the wake site there is\nunreachable.\n\nIntroduce svc_rdma_xprt_deferred_close(), a thin svcrdma wrapper\nthat calls svc_xprt_deferred_close() and then wakes both\nsc_sq_ticket_wait and sc_send_wait. Convert the svcrdma producers\nthat called svc_xprt_deferred_close() directly:\nsvc_rdma_cma_handler(), qp_event_handler(),\nsvc_rdma_post_send_err(), svc_rdma_wc_send(), the sendto drop\npath, the rw completion error paths, and the recvfrom flush and\nread-list error paths.\n\nWake both waitqueues from svc_rdma_detach() as well. The\nsynchronous svc_xprt_close() path (backchannel ENOTCONN, device\nremoval via svc_rdma_xprt_done) reaches detach without flowing\nthrough svc_xprt_deferred_close() and therefore does not invoke\nthe new helper.\n\n[ cel: add svc_rdma_xprt_deferred_close() to complete the fix ]"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - An unauthenticated peer can reach the vulnerable NFS/RDMA server over an IP-based RDMA connection, including routable iWARP or RoCE deployments.\nAC:L - The attacker controls concurrent request batching, Send Queue pressure, and the remote disconnect that strands waiters, and can repeat attempts without relying on an uncontrollable race.\nPR:N - Malformed RPC/RDMA headers can reach svc_rdma_sq_wait() through the transport-error reply path before RPC authentication, NFS export authorization, or credential validation.\nUI:N - Exploitation requires only attacker-generated RDMA traffic and disconnection; no victim action is required after the service is listening.\nS:U - The vulnerable transport and affected NFS service threads belong to the same host kernel security authority.\nC:N - The defect is a missed wake-up that pins references and does not disclose data or provide a memory-read primitive.\nI:N - No memory corruption, unintended write, or data modification occurs; retained references prevent premature object destruction.\nA:H - Waiters remain indefinitely in TASK_UNINTERRUPTIBLE, and an attacker can park all NFS service workers and block transport teardown or server shutdown, causing complete service availability loss."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/sunrpc/svc_rdma.h", "net/sunrpc/xprtrdma/svc_rdma_recvfrom.c", "net/sunrpc/xprtrdma/svc_rdma_rw.c", "net/sunrpc/xprtrdma/svc_rdma_sendto.c", "net/sunrpc/xprtrdma/svc_rdma_transport.c"], "versions": [{"version": "ccc89b9d1ed233349cfe8d87b842e7351b74d8de", "lessThan": "40eedc4253dbda0b29b7961200534dfcecb48ace", "status": "affected", "versionType": "git"}, {"version": "ccc89b9d1ed233349cfe8d87b842e7351b74d8de", "lessThan": "e5248a7426030db1e126363f72afdb3b71339a5c", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/sunrpc/svc_rdma.h", "net/sunrpc/xprtrdma/svc_rdma_recvfrom.c", "net/sunrpc/xprtrdma/svc_rdma_rw.c", "net/sunrpc/xprtrdma/svc_rdma_sendto.c", "net/sunrpc/xprtrdma/svc_rdma_transport.c"], "versions": [{"version": "7.1", "status": "affected"}, {"version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "7.1", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/40eedc4253dbda0b29b7961200534dfcecb48ace"}, {"url": "https://git.kernel.org/stable/c/e5248a7426030db1e126363f72afdb3b71339a5c"}], "title": "svcrdma: wake sq waiters when the transport closes", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/linux/sunrpc/svc_rdma.h", "net/sunrpc/xprtrdma/svc_rdma_recvfrom.c", "net/sunrpc/xprtrdma/svc_rdma_rw.c", "net/sunrpc/xprtrdma/svc_rdma_sendto.c", "net/sunrpc/xprtrdma/svc_rdma_transport.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "40eedc4253dbda0b29b7961200534dfcecb48ace", "status": "affected", "version": "ccc89b9d1ed233349cfe8d87b842e7351b74d8de", "versionType": "git"}, {"lessThan": "e5248a7426030db1e126363f72afdb3b71339a5c", "status": "affected", "version": "ccc89b9d1ed233349cfe8d87b842e7351b74d8de", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/linux/sunrpc/svc_rdma.h", "net/sunrpc/xprtrdma/svc_rdma_recvfrom.c", "net/sunrpc/xprtrdma/svc_rdma_rw.c", "net/sunrpc/xprtrdma/svc_rdma_sendto.c", "net/sunrpc/xprtrdma/svc_rdma_transport.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.1"}, {"lessThan": "7.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "7D22B17B-4F96-43BE-835F-3A80228838B0", "versionEndExcluding": "7.1.4", "versionStartIncluding": "7.1", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: wake sq waiters when the transport closes\n\nThreads parked in svc_rdma_sq_wait() on sc_sq_ticket_wait or\nsc_send_wait can hang indefinitely in TASK_UNINTERRUPTIBLE state\nacross transport teardown, pinning svc_xprt references and\nblocking svc_rdma_free().\n\nThe close path sets XPT_CLOSE before invoking xpo_detach and both\nwait_event predicates include an XPT_CLOSE term, but the\npredicates are re-evaluated only on wakeup. sc_sq_ticket_wait has\nno completion-driven wake path; it is advanced solely by the\nchained ticket handoff inside svc_rdma_sq_wait() itself. Without\nan explicit wake at close, parked threads never observe\nXPT_CLOSE, hold their svc_xprt_get reference forever, and\nsvc_rdma_free() blocks on xpt_ref dropping to zero.\n\nTwo close entry points reach this transport. Local teardown runs\nsvc_rdma_detach() from svc_handle_xprt() -> svc_delete_xprt() ->\nxpo_detach() on a worker thread. A remote disconnect arrives at\nsvc_rdma_cma_handler(), which calls svc_xprt_deferred_close():\nthat sets XPT_CLOSE and enqueues the transport but does not\naccess either RDMA waitqueue, so a worker already parked in\nsvc_rdma_sq_wait() never re-evaluates its predicate. With every\nworker parked on this transport, no thread is available to run\nthe local teardown either, and the wake site there is\nunreachable.\n\nIntroduce svc_rdma_xprt_deferred_close(), a thin svcrdma wrapper\nthat calls svc_xprt_deferred_close() and then wakes both\nsc_sq_ticket_wait and sc_send_wait. Convert the svcrdma producers\nthat called svc_xprt_deferred_close() directly:\nsvc_rdma_cma_handler(), qp_event_handler(),\nsvc_rdma_post_send_err(), svc_rdma_wc_send(), the sendto drop\npath, the rw completion error paths, and the recvfrom flush and\nread-list error paths.\n\nWake both waitqueues from svc_rdma_detach() as well. The\nsynchronous svc_xprt_close() path (backchannel ENOTCONN, device\nremoval via svc_rdma_xprt_done) reaches detach without flowing\nthrough svc_xprt_deferred_close() and therefore does not invoke\nthe new helper.\n\n[ cel: add svc_rdma_xprt_deferred_close() to complete the fix ]"}], "id": "CVE-2026-64281", "lastModified": "2026-08-17T05:17:27.450", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-07-25T10:17:08.667", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/40eedc4253dbda0b29b7961200534dfcecb48ace"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e5248a7426030db1e126363f72afdb3b71339a5c"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: svcrdma: wake sq waiters when the transport closes", "id": "2507036", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507036"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-772", "details": ["A flaw was found in the Linux kernel's svcrdma component. During transport teardown, threads waiting in `svc_rdma_sq_wait()` can hang indefinitely in an uninterruptible state. This occurs because these threads are not explicitly woken up when the transport closes, leading to them continuously holding references to `svc_xprt`. Consequently, this can block the `svc_rdma_free()` function, resulting in a denial of service (DoS) condition."], "name": "CVE-2026-64281", "public_date": "2026-07-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64281\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64281\nhttps://lore.kernel.org/linux-cve-announce/2026072502-CVE-2026-64281-6855@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccc89b9d1ed233349cfe8d87b842e7351b74d8de,40eedc4253dbda0b29b7961200534dfcecb48ace)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccc89b9d1ed233349cfe8d87b842e7351b74d8de,e5248a7426030db1e126363f72afdb3b71339a5c)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "7.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,7.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.4,8.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-25T11:45:17.632335+00:00", "updated": "2026-08-13T18:00:04.138700+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}