fkie_cve-2025-40090
Vulnerability from fkie_nvd
Published
2025-10-30 10:15
Modified
2025-10-30 15:03
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix recursive locking in RPC handle list access Since commit 305853cce3794 ("ksmbd: Fix race condition in RPC handle list access"), ksmbd_session_rpc_method() attempts to lock sess->rpc_lock. This causes hung connections / tasks when a client attempts to open a named pipe. Using Samba's rpcclient tool: $ rpcclient //192.168.1.254 -U user%password $ rpcclient $> srvinfo <connection hung here> Kernel side: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:0 pid:5021 tgid:5021 ppid:2 flags:0x00200000 Workqueue: ksmbd-io handle_ksmbd_work Call trace: __schedule from schedule+0x3c/0x58 schedule from schedule_preempt_disabled+0xc/0x10 schedule_preempt_disabled from rwsem_down_read_slowpath+0x1b0/0x1d8 rwsem_down_read_slowpath from down_read+0x28/0x30 down_read from ksmbd_session_rpc_method+0x18/0x3c ksmbd_session_rpc_method from ksmbd_rpc_open+0x34/0x68 ksmbd_rpc_open from ksmbd_session_rpc_open+0x194/0x228 ksmbd_session_rpc_open from create_smb2_pipe+0x8c/0x2c8 create_smb2_pipe from smb2_open+0x10c/0x27ac smb2_open from handle_ksmbd_work+0x238/0x3dc handle_ksmbd_work from process_scheduled_works+0x160/0x25c process_scheduled_works from worker_thread+0x16c/0x1e8 worker_thread from kthread+0xa8/0xb8 kthread from ret_from_fork+0x14/0x38 Exception stack(0x8529ffb0 to 0x8529fff8) The task deadlocks because the lock is already held: ksmbd_session_rpc_open down_write(&sess->rpc_lock) ksmbd_rpc_open ksmbd_session_rpc_method down_read(&sess->rpc_lock) <-- deadlock Adjust ksmbd_session_rpc_method() callers to take the lock when necessary.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3412fbd81b46b9cfae013817b61d4bbd27e09e36
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4602b8cee1481dbb896182e5cb1e8cf12910e9e7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/88f170814fea74911ceab798a43cbd7c5599bed4
Impacted products
Vendor Product Version


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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix recursive locking in RPC handle list access\n\nSince commit 305853cce3794 (\"ksmbd: Fix race condition in RPC handle list\naccess\"), ksmbd_session_rpc_method() attempts to lock sess-\u003erpc_lock.\n\nThis causes hung connections / tasks when a client attempts to open\na named pipe. Using Samba\u0027s rpcclient tool:\n\n $ rpcclient //192.168.1.254 -U user%password\n $ rpcclient $\u003e srvinfo\n \u003cconnection hung here\u003e\n\nKernel side:\n  \"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n  task:kworker/0:0 state:D stack:0 pid:5021 tgid:5021 ppid:2 flags:0x00200000\n  Workqueue: ksmbd-io handle_ksmbd_work\n  Call trace:\n  __schedule from schedule+0x3c/0x58\n  schedule from schedule_preempt_disabled+0xc/0x10\n  schedule_preempt_disabled from rwsem_down_read_slowpath+0x1b0/0x1d8\n  rwsem_down_read_slowpath from down_read+0x28/0x30\n  down_read from ksmbd_session_rpc_method+0x18/0x3c\n  ksmbd_session_rpc_method from ksmbd_rpc_open+0x34/0x68\n  ksmbd_rpc_open from ksmbd_session_rpc_open+0x194/0x228\n  ksmbd_session_rpc_open from create_smb2_pipe+0x8c/0x2c8\n  create_smb2_pipe from smb2_open+0x10c/0x27ac\n  smb2_open from handle_ksmbd_work+0x238/0x3dc\n  handle_ksmbd_work from process_scheduled_works+0x160/0x25c\n  process_scheduled_works from worker_thread+0x16c/0x1e8\n  worker_thread from kthread+0xa8/0xb8\n  kthread from ret_from_fork+0x14/0x38\n  Exception stack(0x8529ffb0 to 0x8529fff8)\n\nThe task deadlocks because the lock is already held:\n  ksmbd_session_rpc_open\n    down_write(\u0026sess-\u003erpc_lock)\n    ksmbd_rpc_open\n      ksmbd_session_rpc_method\n        down_read(\u0026sess-\u003erpc_lock)   \u003c-- deadlock\n\nAdjust ksmbd_session_rpc_method() callers to take the lock when necessary."
    }
  ],
  "id": "CVE-2025-40090",
  "lastModified": "2025-10-30T15:03:13.440",
  "metrics": {},
  "published": "2025-10-30T10:15:33.537",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3412fbd81b46b9cfae013817b61d4bbd27e09e36"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4602b8cee1481dbb896182e5cb1e8cf12910e9e7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/88f170814fea74911ceab798a43cbd7c5599bed4"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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