{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31557", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.116Z", "datePublished": "2026-04-24T14:35:40.544Z", "dateUpdated": "2026-08-05T12:23:29.694Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:23:29.694Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable async event and teardown path is reachable through NVMe-oF target networking, including nvmet-tcp, by connecting to the target, issuing an admin Async Event Request, and disconnecting.\nAC:L - The attacker controls both relevant actions: queuing async event work and triggering connection teardown. No uncontrollable memory layout or victim timing condition is required beyond repeating the network sequence.\nPR:N - The NVMe discovery controller is reachable with the standard discovery NQN, allows hosts by design, supports async event requests, and skips DH-HMAC-CHAP authentication. In an exposed nvmet-tcp deployment this is reachable without credentials.\nUI:N - No victim user action is needed after the target service is exposed. The remote peer can trigger the sequence by protocol messages and disconnecting.\nS:U - The impact is confined to the kernel/NVMe target host that processes the malicious connection. It does not cross a VM, IOMMU, or separate security authority boundary.\nC:N - The bug is a workqueue/flush recursion issue and does not expose kernel memory or target data. There is no identified read primitive.\nI:N - The issue does not corrupt memory or provide a write/control-flow primitive. It affects teardown/workqueue progress rather than data integrity.\nA:H - The recursive workqueue flush can trigger a kernel lockdep warning and can lead to a panic or teardown hang in hardened/debug configurations. It can be triggered repeatedly over the network, so availability impact is scored high." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/admin-cmd.c", "drivers/nvme/target/core.c", "drivers/nvme/target/nvmet.h", "drivers/nvme/target/rdma.c" ], "versions": [ { "version": "8832cf922151e9dfa2821736beb0ae2dd3968b6e", "lessThan": "49c7c50ee6325a084216e94395e067ecde8088fa", "status": "affected", "versionType": "git" }, { "version": "8832cf922151e9dfa2821736beb0ae2dd3968b6e", "lessThan": "ca111c9d8d6c9d5735878d933a1716c4be86c2d1", "status": "affected", "versionType": "git" }, { "version": "8832cf922151e9dfa2821736beb0ae2dd3968b6e", "lessThan": "25ceffc1dabec3b93f458b437aae26f4da293f87", "status": "affected", "versionType": "git" }, { "version": "8832cf922151e9dfa2821736beb0ae2dd3968b6e", "lessThan": "2922e3507f6d5caa7f1d07f145e186fc6f317a4e", "status": "affected", "versionType": "git" }, { "version": "d44ff3b100b94e9f23b1e8dbe688eee9bb867ac9", "status": "affected", "versionType": "git" }, { "version": "84026f8c9357c62a9d3e4c554ffd10ccab813654", "status": "affected", "versionType": "git" }, { "version": "5.15.42", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "5.17.10", "lessThan": "5.18", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/admin-cmd.c", "drivers/nvme/target/core.c", "drivers/nvme/target/nvmet.h", "drivers/nvme/target/rdma.c" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.80", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.21", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.11", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.80" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.21" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.19.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.0" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17.10" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/49c7c50ee6325a084216e94395e067ecde8088fa" }, { "url": "https://git.kernel.org/stable/c/ca111c9d8d6c9d5735878d933a1716c4be86c2d1" }, { "url": "https://git.kernel.org/stable/c/25ceffc1dabec3b93f458b437aae26f4da293f87" }, { "url": "https://git.kernel.org/stable/c/2922e3507f6d5caa7f1d07f145e186fc6f317a4e" } ], "title": "nvmet: move async event work off nvmet-wq", "x_generator": { "engine": "bippy-1.2.0" } } } }