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.
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.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 27 May 2026 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-362 |
Wed, 27 May 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | tcp: call sk_data_ready() after listener migration | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-27T12:56:17.249Z
Reserved: 2026-05-13T15:03:33.092Z
Link: CVE-2026-46015
No data.
Status : Awaiting Analysis
Published: 2026-05-27T14:17:19.840
Modified: 2026-05-27T14:48:03.013
Link: CVE-2026-46015
No data.
OpenCVE Enrichment
Updated: 2026-05-27T17:00:17Z
Weaknesses
No weakness.