{"api_version":"1","generated_at":"2026-09-10T22:38:12+00:00","cve":"CVE-2026-80920","urls":{"html":"https://cve.report/CVE-2026-80920","api":"https://cve.report/api/cve/CVE-2026-80920.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80920","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80920"},"summary":{"title":"io_uring: defer eventfd signaling when queued from a wakeup handler","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: defer eventfd signaling when queued from a wakeup handler\n\nio_req_local_work_add() signals the CQ ring eventfd inline when it is the\none to push the first entry onto ->work_list. For DEFER_TASKRUN rings that\nadd is frequently done from a waitqueue wakeup handler, where an\narbitrary waitqueue lock is held.\n\neventfd_signal_mask() only refuses to recurse when current->in_eventfd\nis set, but that bit is set by eventfd_signal_mask() itself. If the wake\nchain starts somewhere else, signal goes out inline and can feed back\ninto epoll.\n\nAdd IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three\nwaitqueue callbacks, and use it to force io_eventfd_signal() down the\nexisting call_rcu_hurry() deferral instead of signaling inline.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-09 17:17:47","updated_at":"2026-09-09 17:17:47"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f","name":"https://git.kernel.org/stable/c/b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e","name":"https://git.kernel.org/stable/c/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a","name":"https://git.kernel.org/stable/c/40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e22f4494cc9487d326e5e3067f33dea7c1e442b2","name":"https://git.kernel.org/stable/c/e22f4494cc9487d326e5e3067f33dea7c1e442b2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80920","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80920","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 21a091b970cdbcf3e8ff829234b51be6f9192766 e22f4494cc9487d326e5e3067f33dea7c1e442b2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 21a091b970cdbcf3e8ff829234b51be6f9192766 b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 21a091b970cdbcf3e8ff829234b51be6f9192766 40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 21a091b970cdbcf3e8ff829234b51be6f9192766 cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.49 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.11 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.1 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":["include/linux/io_uring_types.h","io_uring/eventfd.c","io_uring/eventfd.h","io_uring/futex.c","io_uring/io_uring.c","io_uring/poll.c","io_uring/tw.c","io_uring/waitid.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"e22f4494cc9487d326e5e3067f33dea7c1e442b2","status":"affected","version":"21a091b970cdbcf3e8ff829234b51be6f9192766","versionType":"git"},{"lessThan":"b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f","status":"affected","version":"21a091b970cdbcf3e8ff829234b51be6f9192766","versionType":"git"},{"lessThan":"40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a","status":"affected","version":"21a091b970cdbcf3e8ff829234b51be6f9192766","versionType":"git"},{"lessThan":"cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e","status":"affected","version":"21a091b970cdbcf3e8ff829234b51be6f9192766","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/linux/io_uring_types.h","io_uring/eventfd.c","io_uring/eventfd.h","io_uring/futex.c","io_uring/io_uring.c","io_uring/poll.c","io_uring/tw.c","io_uring/waitid.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.1"},{"lessThan":"6.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.49","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.11","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.1","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":"6.18.49","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.11","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.1","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: defer eventfd signaling when queued from a wakeup handler\n\nio_req_local_work_add() signals the CQ ring eventfd inline when it is the\none to push the first entry onto ->work_list. For DEFER_TASKRUN rings that\nadd is frequently done from a waitqueue wakeup handler, where an\narbitrary waitqueue lock is held.\n\neventfd_signal_mask() only refuses to recurse when current->in_eventfd\nis set, but that bit is set by eventfd_signal_mask() itself. If the wake\nchain starts somewhere else, signal goes out inline and can feed back\ninto epoll.\n\nAdd IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three\nwaitqueue callbacks, and use it to force io_eventfd_signal() down the\nexisting call_rcu_hurry() deferral instead of signaling inline."}],"providerMetadata":{"dateUpdated":"2026-09-09T16:13:17.023Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/e22f4494cc9487d326e5e3067f33dea7c1e442b2"},{"url":"https://git.kernel.org/stable/c/b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f"},{"url":"https://git.kernel.org/stable/c/40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a"},{"url":"https://git.kernel.org/stable/c/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e"}],"title":"io_uring: defer eventfd signaling when queued from a wakeup handler","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80920","datePublished":"2026-09-09T16:13:17.023Z","dateReserved":"2026-08-26T14:34:25.801Z","dateUpdated":"2026-09-09T16:13:17.023Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-09 17:17:47","lastModifiedDate":"2026-09-09 17:17:47","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80920","Ordinal":"1","Title":"io_uring: defer eventfd signaling when queued from a wakeup hand","CVE":"CVE-2026-80920","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80920","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: defer eventfd signaling when queued from a wakeup handler\n\nio_req_local_work_add() signals the CQ ring eventfd inline when it is the\none to push the first entry onto ->work_list. For DEFER_TASKRUN rings that\nadd is frequently done from a waitqueue wakeup handler, where an\narbitrary waitqueue lock is held.\n\neventfd_signal_mask() only refuses to recurse when current->in_eventfd\nis set, but that bit is set by eventfd_signal_mask() itself. If the wake\nchain starts somewhere else, signal goes out inline and can feed back\ninto epoll.\n\nAdd IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three\nwaitqueue callbacks, and use it to force io_eventfd_signal() down the\nexisting call_rcu_hurry() deferral instead of signaling inline.","Type":"Description","Title":"io_uring: defer eventfd signaling when queued from a wakeup hand"}]}}}