{"id":"CVE-2026-99130","title":"io_uring/cancel: don't spin on local work the task can't run","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/cancel: don't spin on local work the task can't run\n\nio_uring_cancel_generic() refuses to sleep while any ring on the exiting\ntask's tctx has local work pendin…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 64e196a6d7173667a2a0fe2f191bc64eecd07778","Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 8a241d7ca23be2695a1fbe587ee12eae061c31af","Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 94d13387b96e50a4288f7bbdfe401189246a11a1","Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 3005459e0ddfcef0f555b6e81f672f2c49a1c0aa","Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < fddcf4c5321b3ea5f72166c3fd36a9d1c34f80c7","Linux 6.4"],"published":"2026-10-28","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:42:03.208Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99130","references":[{"url":"https://git.kernel.org/stable/c/64e196a6d7173667a2a0fe2f191bc64eecd07778"},{"url":"https://git.kernel.org/stable/c/8a241d7ca23be2695a1fbe587ee12eae061c31af"},{"url":"https://git.kernel.org/stable/c/94d13387b96e50a4288f7bbdfe401189246a11a1"},{"url":"https://git.kernel.org/stable/c/3005459e0ddfcef0f555b6e81f672f2c49a1c0aa"},{"url":"https://git.kernel.org/stable/c/fddcf4c5321b3ea5f72166c3fd36a9d1c34f80c7"}],"tags":["cve.org"],"epss":0.00168,"epssPercentile":0.06221,"ingestedAt":"2026-10-28T11:09:40.437Z","slug":"CVE-2026-99130","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/cancel: don't spin on local work the task can't run\n\nio_uring_cancel_generic() refuses to sleep while any ring on the exiting\ntask's tctx has local work pending. It assumes the task is that ring's\nsubmitter and that the next io_uring_try_cancel_requests() pass will run\nthe work. This does not hold for a ring that was still\nIORING_SETUP_R_DISABLED when the task got its tctx node from\nio_uring_create() or io_ringfd_register(). The submitter is set later by\nIORING_REGISTER_ENABLE_RINGS, possibly from another task, and only the\nsubmitter may run local work on an IORING_SETUP_DEFER_TASKRUN ring. To\nthe exiting task the work stays pending forever, the loop never reaches\nschedule(), and the task trips the WARN_ON_ONCE() once and then spins in\ndo_exit().\n\nAn unprivileged user can set this up at will by creating a disabled\nring, having a child enable it and stop, posting to the ring with\nIORING_OP_MSG_RING and exiting with a request in flight that only the\nchild can complete. The exiting thread burns a CPU until the child runs\nor dies, and with panic_on_warn set the WARN panics the kernel.\n\nFix by skipping the sleep only when io_allowed_defer_tw_run() allows the\ntask to run the work. This is reasonable since work it cannot run cannot\ncomplete any of its requests either, so nothing is lost by sleeping.\nDrop the WARN_ON_ONCE() since handing a disabled ring to another thread\nis a supported scenario, not a bug state.\n\n## Affected\n\n- `Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 64e196a6d7173667a2a0fe2f191bc64eecd07778`\n- `Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 8a241d7ca23be2695a1fbe587ee12eae061c31af`\n- `Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 94d13387b96e50a4288f7bbdfe401189246a11a1`\n- `Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < 3005459e0ddfcef0f555b6e81f672f2c49a1c0aa`\n- `Linux >= 360cd42c4e95ff06d8d7b0a54e42236c7e7c187f < fddcf4c5321b3ea5f72166c3fd36a9d1c34f80c7`\n- `Linux 6.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}