Bug 2552230 (CVE-2026-98422)

Summary: CVE-2026-98422 kernel: wifi: mac80211: reset the AP_VLAN tailroom counter on ifdown
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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A flaw was found in the Linux kernel's mac80211 wireless subsystem. A local user with network administration privileges can cause a Denial of Service (DoS) by repeatedly activating and deactivating Access Point Virtual Local Area Network (AP_VLAN) interfaces. When an AP_VLAN interface is stopped, the kernel fails to reset an internal cryptographic buffer counter. Bringing the interface back up causes this counter to continuously increment, eventually triggering a kernel sanity check failure and potential system crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-14 13:53:25 UTC
In the Linux kernel, the following vulnerability has been resolved:

wifi: mac80211: reset the AP_VLAN tailroom counter on ifdown

On ifup, AP_VLAN interfaces get crypto_tx_tailroom_needed_cnt from
the AP interface, but it's never decremented again unless the AP is
also brought down. Thus, bringing the same AP_VLAN up again will
increment the counter again and eventually hit the sanity check:

  WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
               master->crypto_tx_tailroom_needed_cnt);

Reset it on ifdown to avoid that.