FKIE_CVE-2026-46015
Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-06-01 17:17
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
Impacted products
| Vendor | Product | Version |
|---|
{
"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": "2026-06-01T17:17:18.063",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"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/14e9bb6eba8f59dcc637702e4744ae5e30660d76"
},
{
"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/7aa7933a5607b1e5b56f322d17265c1d0ea02c51"
},
{
"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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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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