)]}' { "commit": "7ead0fd4c30a3ac938a51edf82fd36b526ffa21b", "tree": "836bbe3aafb035f63d503e84015035aca7b00a87", "parents": [ "29a4249f1496489d424ca86f59a68b56510862a6" ], "author": { "name": "Chaitanya Kulkarni", "email": "kch@nvidia.com", "time": "Wed Apr 08 17:56:47 2026 -0700" }, "committer": { "name": "Kevin Liu", "email": "zhihuil@google.com", "time": "Wed Jun 10 14:35:24 2026 -0700" }, "message": "nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free\n\ncommit aade8abd8b868b6ffa9697aadaea28ec7f65bee6 upstream.\n\nnvmet_tcp_release_queue_work() runs on nvmet-wq and can drop the\nfinal controller reference through nvmet_cq_put(). If that triggers\nnvmet_ctrl_free(), the teardown path flushes ctrl-\u003easync_event_work on\nthe same nvmet-wq.\n\nCall chain:\n\n nvmet_tcp_schedule_release_queue()\n kref_put(\u0026queue-\u003ekref, nvmet_tcp_release_queue)\n nvmet_tcp_release_queue()\n queue_work(nvmet_wq, \u0026queue-\u003erelease_work) \u003c--- nvmet_wq\n process_one_work()\n nvmet_tcp_release_queue_work()\n nvmet_cq_put(\u0026queue-\u003envme_cq)\n nvmet_cq_destroy()\n nvmet_ctrl_put(cq-\u003ectrl)\n nvmet_ctrl_free()\n flush_work(\u0026ctrl-\u003easync_event_work) \u003c--- nvmet_wq\n\n Previously Scheduled by :-\n\t\t nvmet_add_async_event\n\t\t queue_work(nvmet_wq, \u0026ctrl-\u003easync_event_work);\n\nThis trips lockdep with a possible recursive locking warning.\n\n[ 5223.015876] run blktests nvme/003 at 2026-04-07 20:53:55\n[ 5223.061801] loop0: detected capacity change from 0 to 2097152\n[ 5223.072206] nvmet: adding nsid 1 to subsystem blktests-subsystem-1\n[ 5223.088368] nvmet_tcp: enabling port 0 (127.0.0.1:4420)\n[ 5223.126086] nvmet: Created discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.\n[ 5223.128453] nvme nvme1: new ctrl: NQN \"nqn.2014-08.org.nvmexpress.discovery\", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349\n[ 5233.199447] nvme nvme1: Removing ctrl: NQN \"nqn.2014-08.org.nvmexpress.discovery\"\n\n[ 5233.227718] \u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n[ 5233.231283] WARNING: possible recursive locking detected\n[ 5233.234696] 7.0.0-rc3nvme+ #20 Tainted: G O N\n[ 5233.238434] --------------------------------------------\n[ 5233.241852] kworker/u192:6/2413 is trying to acquire lock:\n[ 5233.245429] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90\n[ 5233.251438]\n but task is already holding lock:\n[ 5233.255254] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0\n[ 5233.261125]\n other info that might help us debug this:\n[ 5233.265333] Possible unsafe locking scenario:\n\n[ 5233.269217] CPU0\n[ 5233.270795] ----\n[ 5233.272436] lock((wq_completion)nvmet-wq);\n[ 5233.275241] lock((wq_completion)nvmet-wq);\n[ 5233.278020]\n *** DEADLOCK ***\n\n[ 5233.281793] May be due to missing lock nesting notation\n\n[ 5233.286195] 3 locks held by kworker/u192:6/2413:\n[ 5233.289192] #0: ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0\n[ 5233.294569] #1: ffffc9000e2a7e40 ((work_completion)(\u0026queue-\u003erelease_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x6e0\n[ 5233.300128] #2: ffffffff82d7dc40 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530\n[ 5233.304290]\n stack backtrace:\n[ 5233.306520] CPU: 4 UID: 0 PID: 2413 Comm: kworker/u192:6 Tainted: G O N 7.0.0-rc3nvme+ #20 PREEMPT(full)\n[ 5233.306524] Tainted: [O]\u003dOOT_MODULE, [N]\u003dTEST\n[ 5233.306525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\n[ 5233.306527] Workqueue: nvmet-wq nvmet_tcp_release_queue_work [nvmet_tcp]\n[ 5233.306532] Call Trace:\n[ 5233.306534] \u003cTASK\u003e\n[ 5233.306536] dump_stack_lvl+0x73/0xb0\n[ 5233.306552] print_deadlock_bug+0x225/0x2f0\n[ 5233.306556] __lock_acquire+0x13f0/0x2290\n[ 5233.306563] lock_acquire+0xd0/0x300\n[ 5233.306565] ? touch_wq_lockdep_map+0x26/0x90\n[ 5233.306571] ? __flush_work+0x20b/0x530\n[ 5233.306573] ? touch_wq_lockdep_map+0x26/0x90\n[ 5233.306577] touch_wq_lockdep_map+0x3b/0x90\n[ 5233.306580] ? touch_wq_lockdep_map+0x26/0x90\n[ 5233.306583] ? __flush_work+0x20b/0x530\n[ 5233.306585] __flush_work+0x268/0x530\n[ 5233.306588] ? __pfx_wq_barrier_func+0x10/0x10\n[ 5233.306594] ? xen_error_entry+0x30/0x60\n[ 5233.306600] nvmet_ctrl_free+0x140/0x310 [nvmet]\n[ 5233.306617] nvmet_cq_put+0x74/0x90 [nvmet]\n[ 5233.306629] nvmet_tcp_release_queue_work+0x19f/0x360 [nvmet_tcp]\n[ 5233.306634] process_one_work+0x206/0x6e0\n[ 5233.306640] worker_thread+0x184/0x320\n[ 5233.306643] ? __pfx_worker_thread+0x10/0x10\n[ 5233.306646] kthread+0xf1/0x130\n[ 5233.306648] ? __pfx_kthread+0x10/0x10\n[ 5233.306651] ret_from_fork+0x355/0x450\n[ 5233.306653] ? __pfx_kthread+0x10/0x10\n[ 5233.306656] ret_from_fork_asm+0x1a/0x30\n[ 5233.306664] \u003c/TASK\u003e\n\nThere is also no need to flush async_event_work from controller\nteardown. The admin queue teardown already fails outstanding AER\nrequests before the final controller put :-\n\n nvmet_sq_destroy(admin sq)\n nvmet_async_events_failall(ctrl)\n\nThe controller has already been removed from the subsystem list before\nnvmet_ctrl_free() quiesces outstanding work.\n\nReplace flush_work() with cancel_work_sync() so a pending\nasync_event_work item is canceled and a running instance is waited on\nwithout recursing into the same workqueue.\n\nBUG\u003db/521759838\nTEST\u003dpresubmit\nRELEASE_NOTE\u003dFixed CVE-2026-46304 in the Linux kernel.\n\ncos-patch: security-moderate\nFixes: 06406d81a2d7 (\"nvmet: cancel fatal error and flush async work before free controller\")\nCc: stable@vger.kernel.org\nReviewed-by: Christoph Hellwig \u003chch@lst.de\u003e\nChange-Id: I2586a0191c7af21359f04fd1d7763540c1d586dc\nSigned-off-by: Chaitanya Kulkarni \u003ckch@nvidia.com\u003e\nSigned-off-by: Keith Busch \u003ckbusch@kernel.org\u003e\nSigned-off-by: Greg Kroah-Hartman \u003cgregkh@linuxfoundation.org\u003e\nSigned-off-by: Kernel CVE Triage Automation \u003ccloud-image-kernel-cve-triage-automation@prod.google.com\u003e\nReviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/158585\nTested-by: Cusky Presubmit Bot \u003cpresubmit@cos-infra-prod.iam.gserviceaccount.com\u003e\nReviewed-by: Kevin Liu \u003czhihuil@google.com\u003e\nReviewed-by: Daniel Velasquez \u003crdvelasquez@google.com\u003e\n", "tree_diff": [ { "type": "modify", "old_id": "1cf6dfac1836151723dcbcac820de2bfd4b5534a", "old_mode": 33188, "old_path": "drivers/nvme/target/core.c", "new_id": "5a2adfc7c796ab3be6684e3f897f555ed40ffc2e", "new_mode": 33188, "new_path": "drivers/nvme/target/core.c" } ] }