Bug 2546363 (CVE-2026-98235)

Summary: CVE-2026-98235 kernel: net/sched: act_api: release tail references on DELACTION failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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   
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Doc Text:
A flaw was found in the Linux kernel's network traffic control subsystem. When processing a batched request to delete traffic actions, a failure encountered on an action bound to a filter causes the cleanup process to terminate prematurely without releasing references on subsequent actions. A local user with network administration privileges could exploit this flaw by issuing a crafted deletion request, resulting in a reference count leak that can lead to resource exhaustion and a denial of service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-06 09:06:04 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net/sched: act_api: release tail references on DELACTION failure

A batched RTM_DELACTION request takes a temporary reference on each
action before attempting any deletion. tcf_action_delete() clears
each processed slot and drops its temporary reference before attempting
the deletion. If deletion fails, tca_action_gd() calls
tcf_action_put_many() to release the remaining references, but its
tcf_act_for_each_action() iterator stops at the first NULL slot.

When a batch stops at an action bound to a filter, this leaks a
reference on each subsequent action. A later delete of an unbound
action can then return success without removing it from the IDR.

Walk the full array in tcf_action_put_many() and skip NULL slots to
release the references held on the unprocessed actions.
Comment 1 Mauro Matteo Cascella 2026-10-09 15:31:07 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98235.mbox