{"api_version":"1","generated_at":"2026-09-11T22:32:25+00:00","cve":"CVE-2026-89546","urls":{"html":"https://cve.report/CVE-2026-89546","api":"https://cve.report/api/cve/CVE-2026-89546.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89546","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89546"},"summary":{"title":"SUNRPC: close backchannel before destroying callback service","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: close backchannel before destroying callback service\n\nA backchannel receive can complete a request while the NFS callback\nservice is being torn down.  xprt_complete_bc_request() removes the\nrequest from bc_pa_list, drops bc_alloc_count, marks the request in use,\nand then asks xprt_enqueue_bc_request() to hand it to the callback\nservice.\n\nIf teardown has already cleared xprt->bc_serv, xprt_enqueue_bc_request()\ncurrently returns without enqueueing or freeing the committed request.\nThe xprt_get() taken on entry is leaked as well.  If the producer wins\nthe race before bc_serv is cleared, it can also enqueue onto sv_cb_list\nafter nfs_callback_down() has stopped the callback threads, leaving the\nrequest linked to a svc_serv that is about to be freed.\n\nClose the producer side before callback threads are stopped.  Add\nxprt_svc_shutdown_bc() to clear xprt->bc_serv under bc_pa_lock, and call\nit on callback shutdown and callback-start failure before stopping the\nservice threads.  Requests that lose the NULL transition in\nxprt_enqueue_bc_request() are released through the normal backchannel\nfree path after balancing bc_slot_count.  Finally, drain any remaining\nsv_cb_list requests after the callback threads have stopped and before\nsvc_destroy() frees the service.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:37","updated_at":"2026-09-11 20:19:37"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/3674f780f47d2906b5a0f7199b66973067bdfeca","name":"https://git.kernel.org/stable/c/3674f780f47d2906b5a0f7199b66973067bdfeca","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6debde9e3e6ae21dcca75837b4247b13ca4ea2b8","name":"https://git.kernel.org/stable/c/6debde9e3e6ae21dcca75837b4247b13ca4ea2b8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89546","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89546","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 441244d4273a8037b265fd254dfdaca5fa736ee2 6debde9e3e6ae21dcca75837b4247b13ca4ea2b8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 441244d4273a8037b265fd254dfdaca5fa736ee2 3674f780f47d2906b5a0f7199b66973067bdfeca git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.19","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/nfs/callback.c","include/linux/sunrpc/bc_xprt.h","net/sunrpc/backchannel_rqst.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6debde9e3e6ae21dcca75837b4247b13ca4ea2b8","status":"affected","version":"441244d4273a8037b265fd254dfdaca5fa736ee2","versionType":"git"},{"lessThan":"3674f780f47d2906b5a0f7199b66973067bdfeca","status":"affected","version":"441244d4273a8037b265fd254dfdaca5fa736ee2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/nfs/callback.c","include/linux/sunrpc/bc_xprt.h","net/sunrpc/backchannel_rqst.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.19"},{"lessThan":"6.19","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.19","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: close backchannel before destroying callback service\n\nA backchannel receive can complete a request while the NFS callback\nservice is being torn down.  xprt_complete_bc_request() removes the\nrequest from bc_pa_list, drops bc_alloc_count, marks the request in use,\nand then asks xprt_enqueue_bc_request() to hand it to the callback\nservice.\n\nIf teardown has already cleared xprt->bc_serv, xprt_enqueue_bc_request()\ncurrently returns without enqueueing or freeing the committed request.\nThe xprt_get() taken on entry is leaked as well.  If the producer wins\nthe race before bc_serv is cleared, it can also enqueue onto sv_cb_list\nafter nfs_callback_down() has stopped the callback threads, leaving the\nrequest linked to a svc_serv that is about to be freed.\n\nClose the producer side before callback threads are stopped.  Add\nxprt_svc_shutdown_bc() to clear xprt->bc_serv under bc_pa_lock, and call\nit on callback shutdown and callback-start failure before stopping the\nservice threads.  Requests that lose the NULL transition in\nxprt_enqueue_bc_request() are released through the normal backchannel\nfree path after balancing bc_slot_count.  Finally, drain any remaining\nsv_cb_list requests after the callback threads have stopped and before\nsvc_destroy() frees the service."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:44:21.898Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/6debde9e3e6ae21dcca75837b4247b13ca4ea2b8"},{"url":"https://git.kernel.org/stable/c/3674f780f47d2906b5a0f7199b66973067bdfeca"}],"title":"SUNRPC: close backchannel before destroying callback service","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89546","datePublished":"2026-09-11T19:44:21.898Z","dateReserved":"2026-09-11T19:38:34.722Z","dateUpdated":"2026-09-11T19:44:21.898Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:37","lastModifiedDate":"2026-09-11 20:19:37","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89546","Ordinal":"1","Title":"SUNRPC: close backchannel before destroying callback service","CVE":"CVE-2026-89546","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89546","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: close backchannel before destroying callback service\n\nA backchannel receive can complete a request while the NFS callback\nservice is being torn down.  xprt_complete_bc_request() removes the\nrequest from bc_pa_list, drops bc_alloc_count, marks the request in use,\nand then asks xprt_enqueue_bc_request() to hand it to the callback\nservice.\n\nIf teardown has already cleared xprt->bc_serv, xprt_enqueue_bc_request()\ncurrently returns without enqueueing or freeing the committed request.\nThe xprt_get() taken on entry is leaked as well.  If the producer wins\nthe race before bc_serv is cleared, it can also enqueue onto sv_cb_list\nafter nfs_callback_down() has stopped the callback threads, leaving the\nrequest linked to a svc_serv that is about to be freed.\n\nClose the producer side before callback threads are stopped.  Add\nxprt_svc_shutdown_bc() to clear xprt->bc_serv under bc_pa_lock, and call\nit on callback shutdown and callback-start failure before stopping the\nservice threads.  Requests that lose the NULL transition in\nxprt_enqueue_bc_request() are released through the normal backchannel\nfree path after balancing bc_slot_count.  Finally, drain any remaining\nsv_cb_list requests after the callback threads have stopped and before\nsvc_destroy() frees the service.","Type":"Description","Title":"SUNRPC: close backchannel before destroying callback service"}]}}}