VulnerabilityPublished 28 Oct 2026

CVE-2026-99166: Linux kernel · net: rds: fix uninitialized trans dereference in CM event handler

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in ca14c289ed9ffed6cc64290d039e923e5720a8bf : update Linux kernel when convenient.

Data as of 28 Oct 2026, 10:58 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

Patch: Available – fixed in ca14c289ed9ffed6cc64290d039e923e5720a8bf, 492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8, 5f23e4e3a31dacfd82a8f56be253adc0910ee84f

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to ca14c289ed9ffed6cc64290d039e923e5720a8bf, 492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8 or 5f23e4e3a31dacfd82a8f56be253adc0910ee84f.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ dcdede0406d30e14a6ed727dce69dfac0518371d, < ca14c289ed9ffed6cc64290d039e923e5720a8bf	Fixed in ca14c289ed9ffed6cc64290d039e923e5720a8bf
LinuxLinux	Affected ≥ dcdede0406d30e14a6ed727dce69dfac0518371d, < 492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8	Fixed in 492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8
LinuxLinux	Affected ≥ dcdede0406d30e14a6ed727dce69dfac0518371d, < 5f23e4e3a31dacfd82a8f56be253adc0910ee84f	Fixed in 5f23e4e3a31dacfd82a8f56be253adc0910ee84f
LinuxLinux	Affected =4.6	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =4.6	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: net: rds: fix uninitialized trans dereference in CM event handler rds_rdma_cm_event_handler_cmn() assigns trans only when the RDMA device is an InfiniBand CA (RDMA_NODE_IB_CA). On any other device type, e.g. an iWARP RNIC such as siw, trans stays uninitialized, but the event switch dereferences it: unconditionally in the RDMA_CM_EVENT_CONNECT_REQUEST case via trans->cm_handle_connect(), and (with a connection context) in the ROUTE_RESOLVED and ESTABLISHED cases. An RDS listener on an iWARP device therefore crashes the kernel as soon as a connect request arrives: with CONFIG_INIT_STACK_ALL_ZERO the wild load becomes a NULL dereference at offset 0xa0 (&trans->cm_handle_connect) in the iw_cm_wq workqueue. GCC masks the bug in default builds by folding the uninitialized load into &rds_ib_transport; Clang-built kernels take the real uninitialized path and oops. The active side can land on a non-IB device too: the id that rds_ib_conn_path_connect() creates is not restricted to a node type, so rdma_resolve_addr() binds it to whichever device serves the local address, and an iWARP RNIC on the same netdev qualifies. The crash there is different: resolving a route on an iWARP id never fills in cm_id->route.path_rec, and the ROUTE_RESOLVED case writes path_rec[0].sl before it calls into the transport. The iWARP transport was dropped long ago and IB is the only transport left, so make that explicit: initialize trans to &rds_ib_transport at declaration, drop the conditional assignment, reject a connect request that arrives on a non-IB device, and drop a connection whose address resolved to one instead of resolving a route on it. The rejection is limited to RDMA_CM_EVENT_CONNECT_REQUEST on purpose: a non-zero return from the handler makes rdma_cm destroy the id the event was delivered on, which is right for the request's freshly created id but would free a connection id that RDS still owns for any other event. On the active side the id stays ic->i_cm_id and the connection's shutdown destroys it, so that case returns 0. [achender: reject only on RDMA_CM_EVENT_CONNECT_REQUEST instead of bailing out for every event on a non-IB device, so that rdma_cm does not destroy connection ids RDS still tracks; drop a connection whose address resolved to a non-IB device before a route is resolved on it; changelog adjusted]

References

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