Bug 2541200 (CVE-2026-97616)

Summary: CVE-2026-97616 kernel: net/sched: act_api: release all action references on NEWACTION failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's traffic control action subsystem. This flaw allows a local user to cause a Denial of Service (DoS) through resource exhaustion. When processing a batched request to replace traffic control actions, an initialization failure causes the cleanup routine to abort prematurely without releasing references for bound actions. Consequently, kernel memory and index slots are leaked, which can prevent further action allocation and degrade system availability.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-25 11:00:06 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net/sched: act_api: release all action references on NEWACTION failure

When a batched RTM_NEWACTION request replaces an existing action,
tcf_idr_check_alloc() takes a temporary reference on it. If a later
action fails to initialize, tcf_action_destroy() uses strict release
semantics to clean up the actions initialized so far. For an action
bound to a filter, the strict check returns -EPERM without dropping
the temporary reference.

This error also makes tcf_action_destroy() return before releasing
subsequent entries. Any new action initialized between the bound
action and the failing entry is leaked together with its reserved
IDR slot, preventing reuse of its index.

Use tcf_idr_release() to drop each reference held by the batch without
rejecting bound actions. This allows cleanup to continue through all
initialized entries and preserves the module reference release when
an action is destroyed. Explicit action deletion and flushing retain
their separate bind-count checks.
Comment 1 Keith Grant 2026-09-29 15:23:18 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97616.mbox