tcp: call sk_data_ready() after listener migration
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 10 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.14 and later | 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27, 7.0.4, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 5.14 and later Fixed in 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27, 7.0.4, 7.1 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.14 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.140; 6.7 to before 6.12.86; 6.13 to before 6.18.27; 6.19 to before 7.0.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.14 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.140; 6.7 to before 6.12.86; 6.13 to before 6.18.27; 6.19 to before 7.0.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27, 7.0.4, 7.1
Red Hat 2 advisories
- RHSA-2026:66180 Released 2026-09-10 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.46.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.46.1.el9_8, kernel-64k-devel-5.14.0-687.46.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.46.1.el9_8, kernel-64k-5.14.0-687.46.1.el9_8, kernel-64k-core-5.14.0-687.46.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.46.1.el9_8, libperf-5.14.0-687.46.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-64k-5.14.0-687.46.1.el9_8, kernel-rt-64k-core-5.14.0-687.46.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-core-5.14.0-687.46.1.el9_8, kernel-rt-debug-5.14.0-687.46.1.el9_8 +9
- RHSA-2026:64775 Released 2026-09-08 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.52.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.52.1.el10_2, kernel-64k-devel-6.12.0-211.52.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.52.1.el10_2, kernel-64k-6.12.0-211.52.1.el10_2, kernel-64k-core-6.12.0-211.52.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.52.1.el10_2, libperf-6.12.0-211.52.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.52.1.el10_2, kernel-rt-64k-6.12.0-211.52.1.el10_2, kernel-rt-64k-core-6.12.0-211.52.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.52.1.el10_2, kernel-rt-core-6.12.0-211.52.1.el10_2, kernel-rt-debug-6.12.0-211.52.1.el10_2 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:64775 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:64775 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:64775 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:64775 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:64775 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:66180 |
Not affected: 2 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-46015
- 2026-10-03 Alias added: GHSA-xg26-4rww-5g68
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
References
Patch 7
- https://git.kernel.org/stable/c/7aa7933a5607b1e5b56f322d17265c1d0ea02c51
- https://git.kernel.org/stable/c/14e9bb6eba8f59dcc637702e4744ae5e30660d76
- https://git.kernel.org/stable/c/ab5fdcd535645f6dbe6e9e21d96a08d141e88b4b
- https://git.kernel.org/stable/c/bebd058ef40c67a81fe6d9ee8beaa4ede90e0704
- https://git.kernel.org/stable/c/83bb57635d7cbafde32f865b577ecfd969f02337
- https://git.kernel.org/stable/c/12625b4da84caf4d84a04988710a7b9bcf702b18
- https://git.kernel.org/stable/c/3864c6ba1e041bc75342353a70fa2a2c6f909923
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- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-46015 · CVE Program
- CVE-2026-46015 · NVD
- FIRST EPSS
- GHSA-xg26-4rww-5g68 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-46015 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences