Kernel warning via stale AP_VLAN tailroom counter
Published Oct 14, 2026 · Updated Oct 14, 2026
Counter mismanagement in Linux mac80211 allows attackers to trigger a kernel warning via repeated AP_VLAN interface cycling. The ieee80211_do_stop function in net/mac80211/iface.c leaves crypto_tx_tailroom_needed_cnt uncleared, so subsequent interface activation adds the parent AP count again. Triggering requires AP_VLAN lifecycle operations while the parent AP remains up; the disclosed consequence is a sanity-check warning, not demonstrated service interruption.
Summary
What happened
Counter mismanagement in Linux mac80211 allows attackers to trigger a kernel warning via repeated AP_VLAN interface cycling. The ieee80211_do_stop function in net/mac80211/iface.c leaves crypto_tx_tailroom_needed_cnt uncleared, so subsequent interface activation adds the parent AP count again. Triggering requires AP_VLAN lifecycle operations while the parent AP remains up; the disclosed consequence is a sanity-check warning, not demonstrated service interruption.
The record
- CVE
- CVE-2026-98422
- Published
- Oct 14, 2026
- Updated
- Oct 14, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Oct 14, 2026CVE publishedPublication date reported by the CVE source.
- Oct 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=4.1
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <304a874670a0b6ab5589a7f60b4af0251797b121
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <3d76b45e8432c0d75fcb9e90d92eaa3176898adf
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <4504f3960dc4501c73be9f99eabda2e26e9db41e
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <4b54d01b48445b66c9e576de92b90a3a3ae7b34a
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <7775759e3cb35ef5a571b2d877c2a9b70a5d5f08
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <875835377d8d62c849b4eb03a7abfafa71d7668f
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <b0b32d3f163d24ea7134380666193bf398e9dc0b
- Affected versionversion=f9dca80b98caac8b4bfb43a2edf1e9f877ccf322 <f6b34a7d64324faf28eedc0f8678b0f832f1cc36
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
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Public exploit references
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Technologies
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