{"cve":"CVE-2026-31557","nvd":{"published":"2026-04-24T15:16:30.080","modified":"2026-10-21T13:18:39.217","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: move async event work off nvmet-wq\n\nFor target nvmet_ctrl_free() flushes ctrl->async_event_work.\nIf nvmet_ctrl_free() runs on nvmet-wq, the flush re-enters workqueue\ncompletion for the same worker:-\n\nA. Async event work queued on nvmet-wq (prior to disconnect):\n  nvmet_execute_async_event()\n     queue_work(nvmet_wq, &ctrl->async_event_work)\n\n  nvmet_add_async_event()\n     queue_work(nvmet_wq, &ctrl->async_event_work)\n\nB. Full pre-work chain (RDMA CM path):\n  nvmet_rdma_cm_handler()\n     nvmet_rdma_queue_disconnect()\n       __nvmet_rdma_queue_disconnect()\n         queue_work(nvmet_wq, &queue->release_work)\n           process_one_work()\n             lock((wq_completion)nvmet-wq)  <--------- 1st\n             nvmet_rdma_release_queue_work()\n\nC. Recursive path (same worker):\n  nvmet_rdma_release_queue_work()\n     nvmet_rdma_free_queue()\n       nvmet_sq_destroy()\n         nvmet_ctrl_put()\n           nvmet_ctrl_free()\n             flush_work(&ctrl->async_event_work)\n               __flush_work()\n                 touch_wq_lockdep_map()\n                 lock((wq_completion)nvmet-wq) <--------- 2nd\n\nLockdep splat:\n\n  ============================================\n  WARNING: possible recursive locking detected\n  6.19.0-rc3nvme+ #14 Tainted: G                 N\n  --------------------------------------------\n  kworker/u192:42/44933 is trying to acquire lock:\n  ffff888118a00948 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90\n\n  but task is already holding lock:\n  ffff888118a00948 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x53e/0x660\n\n  3 locks held by kworker/u192:42/44933:\n   #0: ffff888118a00948 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x53e/0x660\n   #1: ffffc9000e6cbe28 ((work_completion)(&queue->release_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x660\n   #2: ffffffff82d4db60 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530\n\n  Workqueue: nvmet-wq nvmet_rdma_release_queue_work [nvmet_rdma]\n  Call Trace:\n   __flush_work+0x268/0x530\n   nvmet_ctrl_free+0x140/0x310 [nvmet]\n   nvmet_cq_put+0x74/0x90 [nvmet]\n   nvmet_rdma_free_queue+0x23/0xe0 [nvmet_rdma]\n   nvmet_rdma_release_queue_work+0x19/0x50 [nvmet_rdma]\n   process_one_work+0x206/0x660\n   worker_thread+0x184/0x320\n   kthread+0x10c/0x240\n   ret_from_fork+0x319/0x390\n\nMove async event work to a dedicated nvmet-aen-wq to avoid reentrant\nflush on nvmet-wq.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/25ceffc1dabec3b93f458b437aae26f4da293f87","https://git.kernel.org/stable/c/2922e3507f6d5caa7f1d07f145e186fc6f317a4e","https://git.kernel.org/stable/c/49c7c50ee6325a084216e94395e067ecde8088fa","https://git.kernel.org/stable/c/a8a3fb2888e2c4fd5410a19ac1623cc78a2383ec","https://git.kernel.org/stable/c/ca111c9d8d6c9d5735878d933a1716c4be86c2d1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-31557","score":0.00415,"percentile":0.3556,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}