FKIE_CVE-2026-46015

Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: tcp: call sk_data_ready() after listener migration When inet_csk_listen_stop() migrates an established child socket from a closing listener to another socket in the same SO_REUSEPORT group, the target listener gets a new accept-queue entry via inet_csk_reqsk_queue_add(), but that path never notifies the target listener's waiters. A nonblocking accept() still works because it checks the queue directly, but poll()/epoll_wait() waiters and blocking accept() callers can also remain asleep indefinitely. Call READ_ONCE(nsk->sk_data_ready)(nsk) after a successful migration in inet_csk_listen_stop(). However, after inet_csk_reqsk_queue_add() succeeds, the ref acquired in reuseport_migrate_sock() is effectively transferred to nreq->rsk_listener. Another CPU can then dequeue nreq via accept() or listener shutdown, hit reqsk_put(), and drop that listener ref. Since listeners are SOCK_RCU_FREE, wrap the post-queue_add() dereferences of nsk in rcu_read_lock()/rcu_read_unlock(), which also covers the existing sock_net(nsk) access in that path. The reqsk_timer_handler() path does not need the same changes for two reasons: half-open requests become readable only after the final ACK, where tcp_child_process() already wakes the listener; and once nreq is visible via inet_ehash_insert(), the success path no longer touches nsk directly.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/12625b4da84caf4d84a04988710a7b9bcf702b18
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3864c6ba1e041bc75342353a70fa2a2c6f909923
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/83bb57635d7cbafde32f865b577ecfd969f02337
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ab5fdcd535645f6dbe6e9e21d96a08d141e88b4b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bebd058ef40c67a81fe6d9ee8beaa4ede90e0704
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: call sk_data_ready() after listener migration\n\nWhen inet_csk_listen_stop() migrates an established child socket from\na closing listener to another socket in the same SO_REUSEPORT group,\nthe target listener gets a new accept-queue entry via\ninet_csk_reqsk_queue_add(), but that path never notifies the target\nlistener\u0027s waiters. A nonblocking accept() still works because it\nchecks the queue directly, but poll()/epoll_wait() waiters and\nblocking accept() callers can also remain asleep indefinitely.\n\nCall READ_ONCE(nsk-\u003esk_data_ready)(nsk) after a successful migration\nin inet_csk_listen_stop().\n\nHowever, after inet_csk_reqsk_queue_add() succeeds, the ref acquired\nin reuseport_migrate_sock() is effectively transferred to\nnreq-\u003ersk_listener. Another CPU can then dequeue nreq via accept()\nor listener shutdown, hit reqsk_put(), and drop that listener ref.\nSince listeners are SOCK_RCU_FREE, wrap the post-queue_add()\ndereferences of nsk in rcu_read_lock()/rcu_read_unlock(), which also\ncovers the existing sock_net(nsk) access in that path.\n\nThe reqsk_timer_handler() path does not need the same changes for two\nreasons: half-open requests become readable only after the final ACK,\nwhere tcp_child_process() already wakes the listener; and once nreq is\nvisible via inet_ehash_insert(), the success path no longer touches\nnsk directly."
    }
  ],
  "id": "CVE-2026-46015",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:19.840",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/12625b4da84caf4d84a04988710a7b9bcf702b18"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3864c6ba1e041bc75342353a70fa2a2c6f909923"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/83bb57635d7cbafde32f865b577ecfd969f02337"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ab5fdcd535645f6dbe6e9e21d96a08d141e88b4b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bebd058ef40c67a81fe6d9ee8beaa4ede90e0704"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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