{"id":"CVE-2026-80920","revision":"ca6350130456416488e505d4a1378da1","records":[{"revision":"ca6350130456416488e505d4a1378da1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80920","aliases":[],"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":0,"publishedAt":"2026-09-09T16:13:17.023+00:00","modifiedAt":"2026-10-21T12:47:14.401+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/io_uring_types.h\",\n                        \"io_uring/eventfd.c\",\n                        \"io_uring/eventfd.h\",\n                        \"io_uring/futex.c\",\n                        \"io_uring/io_uring.c\",\n                        \"io_uring/poll.c\",\n                        \"io_uring/tw.c\",\n                        \"io_uring/waitid.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"d0c240f25e654442a72af5ca021a02165ccce638\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"9d984451baf768ecd9e1fdad4637b729fcb2c9d5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"e22f4494cc9487d326e5e3067f33dea7c1e442b2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"21a091b970cdbcf3e8ff829234b51be6f9192766\",\n                            \"lessThan\": \"cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/io_uring_types.h\",\n                        \"io_uring/eventfd.c\",\n                        \"io_uring/eventfd.h\",\n                        \"io_uring/futex.c\",\n                        \"io_uring/io_uring.c\",\n                        \"io_uring/poll.c\",\n                        \"io_uring/tw.c\",\n                        \"io_uring/waitid.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.1\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.1\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.160\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.114\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.49\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.11\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.1\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/d0c240f25e654442a72af5ca021a02165ccce638","https://git.kernel.org/stable/c/9d984451baf768ecd9e1fdad4637b729fcb2c9d5","https://git.kernel.org/stable/c/e22f4494cc9487d326e5e3067f33dea7c1e442b2","https://git.kernel.org/stable/c/b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f","https://git.kernel.org/stable/c/40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a","https://git.kernel.org/stable/c/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80920","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80920","identifiers":["CVE-2026-80920"]},"retained":false,"historicalAffected":[]}],"coverage":[]}