* [CVE-2026-98069][MODERATE 7.0] net/rds: acquire the fastpath locks in rds_conn_shutdown() [ Upstream
@ 2026-09-25 14:46 21% AL-KERNEL
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From: AL-KERNEL @ 2026-09-25 14:46 UTC (permalink / raw)
To: kernel-cve
CVE: CVE-2026-98069
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: net/rds: acquire the fastpath locks in rds_conn_shutdown() [ Upstream
Commit: 7febb113795d5de5b690b208f4b0e64a5fad1201
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7febb113795d5de5b690b208f4b0e64a5fad1201
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98069
Analysis date: Fri, 25 Sep 2026 10:46:48 -0400
ActionableScore: 5
ActionableScore lower bound: 4
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES
Summary:
No one-sentence report phrase was found.
======================================================================
ABOUT THIS REPORT
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98069 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98069
The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.
This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.
The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.
Published priority for this report: MODERATE 7.0
Manual review required: YES
A detailed explanation of the methodology and priority rules is included
at the end of this message.
======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================
CVE-2026-98069 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98069 CHECK WITH IMPACT FROM ORIG NN MODERATE Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H';CWE-362;CWE-667;*CWE-664;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '7.5';DESCR 'A race in RDS connection teardown allows rds_send_xmit or rds_ib_recv_refill to reacquire a fast path bit after rds_conn_shutdown has only sampled it as clear. The fast path can then run concurrently with transport shutdown, ring reinitialization, and transmit state reset. Observed symptoms include BUG_ON failures, unexpected operation codes, and NULL pointer dereferences during failover, resulting in at least a kernel crash and denial of service. Concurrent access to transport rings and connection state also creates a plausible memory corruption risk that may extend the impact beyond a crash, although no controlled write or confirmed privilege escalation primitive is demonstrated. For the CVSS the PR:N value is used for the paranoid score because a reachable RDS peer may be able to induce disconnect, reconnect, or competing connection activity without an account on the target. Reliable triggering still requires an enabled and reachable RDS transport, active traffic, and a narrow teardown race window, so AC:H applies. The network exposure is better represented as AV:A because the attacker normally needs access to the same RDS capable storage or cluster network rather than arbitrary Internet reachability. Impact is at least denial of service and in the worst still defensible case may include confidentiality and integrity impact from concurrent transport state corruption.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5) SKIP CVE-2026-98069 UNKNOWN SKIP No affected files built, so skip this CVE NO - - unknown MAYBE LOCK DEADLOCK NULLPTR INIT RACE HARDWARE TEST KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFDH - - checked
======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================
ActionableScore=5
ActionableScoreLower=4
PrimitiveClass=CLASS_B
RealUAF=YES
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
1. ActionableScore
* Raw conservative score: 2
* Conservative score: 4
* Raw paranoid score: 5
* Paranoid score: 5
* Applied conservative floor: 2 -> 4 under REAL UAF FLOOR 4 because an active socket reference can become stale and be consumed after transport teardown, while host-admin privilege is not established.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::
2. Signal breakdown
Conservative signals:
* +2 Real UAF / lifetime violation. Teardown can release the old TCP socket and clear `t_sock` while `rds_tcp_reset_callbacks()` retains and actively uses the previously sampled `osock`.
* +1 Reliable kernel crash / strong DoS. The commit documents `BUG_ON()` failures, unexpected operation codes, and NULL dereferences during failover.
* -1 Hard race. The vulnerable interleaving requires transmit, refill, or callback activity to reacquire a fast-path bit during a narrow teardown window on an affected ordering path.
* Raw total: 2.
Paranoid signals:
* +2 Real UAF / lifetime violation.
* +1 Reliable kernel crash / strong DoS.
* +2 Network-adjacent reachability. An RDS peer can plausibly influence connection loss, reconnect, accepted SYN, and failover activity on an exposed RDS cluster network.
* No race penalty in the paranoid score because repeated failover and connection churn can repeatedly exercise teardown against active fast paths.
* Raw total: 5.
Important non-awarded signals:
* Controlled reclaim or attacker-shaped replacement contents are not demonstrated.
* Arbitrary or directed kernel read/write is not demonstrated.
* Structured stale-object leverage is not separately awarded because meaningful attacker influence over reclaimed socket contents is unresolved.
* Strong LPE leverage, confidentiality, and integrity points are not awarded from the UAF alone.
* No extra Availability point is awarded because the documented crashes and NULL dereferences are the same DoS consequence.
* Concrete repeated release/refcount mutation is not established. There is no visible first release followed by a second lifetime mutation through the exact same reference.
* No repeated-release point or repeated-refcount paranoid point is awarded.
* FLOOR 5 is not applied because controlled reuse, a concrete second lifetime mutation, and attacker-influenced post-free contents are not established.
* Direct Internet-wide reachability is not established.
3. Reachability analysis
The complete conservative attacker boundary is unresolved. RDS applications and peers can exercise transmit and connection activity, but the supplied context does not establish whether an ordinary local user can create the complete affected topology or independently force the required shutdown.
A reachable RDS peer can plausibly influence disconnect, reconnect, failover, and competing SYN processing. This supports network-adjacent reachability in the paranoid model, not unconditional remote reachability in the conservative model. RDS must already be enabled, configured, and reachable, with concurrent transmit, receive-refill, or callback activity.
The patch references network namespaces, but it does not establish that every setup and trigger operation is available through attacker-created namespaces. Therefore `NamespaceScopedPrivilege=UNKNOWN`. No special hardware is required for the TCP path. The IB path requires an RDS/IB deployment, but no hardware penalty is applied because the TCP path is also implicated.
4. Primitive and severity interpretation
The primary primitive is a synchronization and lifetime failure involving active structured transport objects. `rds_conn_shutdown()` only sampled `RDS_IN_XMIT` and `RDS_RECV_REFILL` as clear instead of acquiring them. A fast path could consequently resume while teardown zeroed rings, reset transmit state, or released transport resources.
For the TCP callback path, the supplied context directly states that teardown releases the old socket and clears `t_sock`. Without mutual ownership of `RDS_IN_XMIT`, `rds_tcp_reset_callbacks()` can retain `osock` while teardown changes its lifetime, then consume fields such as `osock->sk`. This is a directly implied active-object UAF rather than fixed stale storage.
This is not a concrete repeated-release case. The evidence shows stale active use, not a second `put`, `release`, or refcount mutation through the same dangling reference.
The demonstrated consequences are kernel crashes, NULL dereferences, assertions, and invalid transport state. Possible reuse of an active socket or corruption caused by simultaneous ring reset and transmission remains unresolved, but controlled reclaim, arbitrary write, disclosure, or privilege escalation is not established.
`PrimitiveClass=CLASS_B` is appropriate. `ImportantCandidate=YES` and `ManualReview=REQUIRED` reflect the active socket lifetime violation and concurrent manipulation of live transport rings, not a claim that Important-grade exploitation is already proven. Automatic downgrade is disallowed because reducing this to an ordinary NULL-dereference DoS would discard the unresolved active-object UAF and ring-state corruption surface.
5. One-sentence report phrase
A race in RDS teardown can release or reset active transport state while send, refill, or TCP callback paths still consume it, producing a host crash and an unresolved active socket use-after-free surface.
6. Manual review recommendation
MANUAL CHECK REQUIRED
Review the exact socket reference ownership, allocator reuse opportunities, RDS socket privilege boundary, and whether an untrusted RDS peer can reliably force teardown while the stale callback or ring path remains active.
7. Call-site confidence
Call-site confidence: high
======================================================================
UPSTREAM PATCH SUMMARY
======================================================================
Patch: net/rds: acquire the fastpath locks in rds_conn_shutdown() [ Upstream
Commit: 7febb113795d5de5b690b208f4b0e64a5fad1201
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7febb113795d5de5b690b208f4b0e64a5fad1201
Changed files:
net/rds/connection.c
net/rds/ib_recv.c
net/rds/send.c
net/rds/tcp.c
Diff excerpt:
Not included in this email. See the upstream URL for the full patch.
Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7febb113795d5de5b690b208f4b0e64a5fad1201
======================================================================
DETAILED REPORT METHODOLOGY
======================================================================
The original Linux kernel CVE announcement for CVE-2026-98069 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98069
The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.
The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.
This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.
The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.
Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:
Conservative CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
The Best / paranoid CVSS vector: AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
The Best / paranoid CVSS score: 7.5
The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.
CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.
A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.
Conservative ActionableScore: 4
Paranoid ActionableScore: 5
The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.
For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:
ActionableScore below 5 -> MODERATE REGULAR
ActionableScore 5 or more -> MODERATE 7.0
The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.
There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).
KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.
AL-KERNEL base severity for this report: MODERATE
KPANIC detected for this report: YES
Published priority for this report (same as in Subject): MODERATE 7.0
These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).
Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is [email protected] (and both
send reply to CVE record itself too and see "reply" button below for howto reply).
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