What’s Vulnerable › Vulnerabilities

CVE-2026-98422: wifi: mac80211: reset the AP_VLAN tailroom counter on ifdown

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-14 · updated 2026-10-19

Description

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.

Affected products

• Linux kernel: 4.1 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/304a874670a0b6ab5589a7f60b4af0251797b121
• https://git.kernel.org/stable/c/3d76b45e8432c0d75fcb9e90d92eaa3176898adf
• https://git.kernel.org/stable/c/4504f3960dc4501c73be9f99eabda2e26e9db41e
• https://git.kernel.org/stable/c/4b54d01b48445b66c9e576de92b90a3a3ae7b34a
• https://git.kernel.org/stable/c/7775759e3cb35ef5a571b2d877c2a9b70a5d5f08
• https://git.kernel.org/stable/c/875835377d8d62c849b4eb03a7abfafa71d7668f
• https://git.kernel.org/stable/c/b0b32d3f163d24ea7134380666193bf398e9dc0b
• https://git.kernel.org/stable/c/f6b34a7d64324faf28eedc0f8678b0f832f1cc36

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