{"api_version":"1","generated_at":"2026-08-01T23:32:14+00:00","cve":"CVE-2026-64281","urls":{"html":"https://cve.report/CVE-2026-64281","api":"https://cve.report/api/cve/CVE-2026-64281.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64281","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64281"},"summary":{"title":"svcrdma: wake sq waiters when the transport closes","description":"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 ]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-25 10:17:08","updated_at":"2026-07-30 15:00:27"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/e5248a7426030db1e126363f72afdb3b71339a5c","name":"https://git.kernel.org/stable/c/e5248a7426030db1e126363f72afdb3b71339a5c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/40eedc4253dbda0b29b7961200534dfcecb48ace","name":"https://git.kernel.org/stable/c/40eedc4253dbda0b29b7961200534dfcecb48ace","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64281","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64281","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ccc89b9d1ed233349cfe8d87b842e7351b74d8de 40eedc4253dbda0b29b7961200534dfcecb48ace git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ccc89b9d1ed233349cfe8d87b842e7351b74d8de e5248a7426030db1e126363f72afdb3b71339a5c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.4 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64281","cve":"CVE-2026-64281","epss":"0.004680000","percentile":"0.380670000","score_date":"2026-07-31","updated_at":"2026-08-01 00:10:34"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"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-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.4","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-27T04:59:25.308Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64281","datePublished":"2026-07-25T08:49:24.399Z","dateReserved":"2026-07-19T15:36:31.777Z","dateUpdated":"2026-07-27T04:59:25.308Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-25 10:17:08","lastModifiedDate":"2026-07-30 15:00:27","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64281","Ordinal":"1","Title":"svcrdma: wake sq waiters when the transport closes","CVE":"CVE-2026-64281","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64281","Ordinal":"1","NoteData":"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 ]","Type":"Description","Title":"svcrdma: wake sq waiters when the transport closes"}]}}}