Unknown

CVE-2026-90081 — net/rds: use wq_has_sleeper() in rds_cong_map_updated()

In the Linux kernel, the following vulnerability has been resolved: net/rds: use wq_has_sleeper() in rds_cong_map_updated() rds_cong_map_updated() runs after a peer's congestion map has been rewritten (by rds_tcp_cong_recv() and rds_ib_cong_recv(), or the clear-all in the loopback and IB send-completion paths). It bumps rds_cong_generation and then checks waitqueue_active() on map->m_waitq and on rds_poll_waitq to decide whether anyone needs waking. atomic_inc() carries no ordering and waitqueue_active() is a plain load, so nothing orders the map and generation stores before the wait queue reads. The waiters do the mirror image: rds_cong_wait() adds itself to m_waitq and then tests the port bit, and rds_poll() registers on rds_poll_waitq and then reads the generation. That is the store-buffering pattern described above waitqueue_active() in include/linux/wait.h - the updater can observe an empty wait queue while the waiter still observes the port as congested, and no wake-up is issued. rds_cong_wait() is an interruptible sleep with no timeout, so a sender blocked on a congested port stays blocked until the next congestion update from that peer arrives or a signal is delivered. A poll() waiter misses the map-updated notification the same way. Use wq_has_sleeper(), which is waitqueue_active() preceded by the required full barrier, as rds_tcp_state_change() already does for the same pattern.

Published Sep 17, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.21%

ahead of 11% of scored CVEs · Oct 18, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < 2a809d7896dbf18e1ecfbdd930f71c9fc298b16d≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < fa4b98e891fda28cc0638d809c6125ec63d8319d≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < 0e169f6a2adeb17b5577ed7e8abd642465bb50ec≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < 42884bd8b8fd023d6a610a695bd5ddd1d5dece17≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < a526214b9f0548ca0e53a6e0d1727d8ea9befc23≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < bf2b8130723efcb5b86c3ddb6317c3a9b2a9cfc5≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < 281f9fda2e06d6c211bb365a5379ed2e05cc2e21≥ 922cb17a5c812fcc9ebee249f4109db099896941 and < d4f484661961636eb90d287050959e613795f73a and 1 more version 2.6.30	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 18, 2026 · 3 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 17, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

10 on the record

git.kernel.org/stable/c/fa4b98e891fda28cc0638d809c6125ec63d8319d
NIST National Vulnerability Database
git.kernel.org/stable/c/bf2b8130723efcb5b86c3ddb6317c3a9b2a9cfc5
NIST National Vulnerability Database
github.com/advisories/GHSA-23r9-76mg-5gpp
GitHub Security Advisories
git.kernel.org/stable/c/d4f484661961636eb90d287050959e613795f73a
NIST National Vulnerability Database
git.kernel.org/stable/c/2a809d7896dbf18e1ecfbdd930f71c9fc298b16d
NIST National Vulnerability Database
git.kernel.org/stable/c/0e169f6a2adeb17b5577ed7e8abd642465bb50ec
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-90081
GitHub Security Advisories
git.kernel.org/stable/c/281f9fda2e06d6c211bb365a5379ed2e05cc2e21
NIST National Vulnerability Database
git.kernel.org/stable/c/a526214b9f0548ca0e53a6e0d1727d8ea9befc23
NIST National Vulnerability Database
git.kernel.org/stable/c/42884bd8b8fd023d6a610a695bd5ddd1d5dece17
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
Unknown CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
Unknown CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
Unknown CVE-2026-98856 kprobes: Skip disarmed probes when checking optkprobe overlap 1d
Unknown CVE-2026-98857 ipvs: bound LBLCR and LBLC cache growth 1d
Unknown CVE-2026-98858 io_uring: fix task_work add use-after-free with SQPOLL 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-90081 is "net/rds: use wq_has_sleeper() in rds_cong_map_updated()", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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