CVE-2026-90408: wifi: ath12k: fix overreads in ath12k_wmi_process_csa_switch_count_event()

Severity: high (CVSS 7.7 v3.1)
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: 2026-09-17 · updated 2026-10-21

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix overreads in ath12k_wmi_process_csa_switch_count_event() There is no policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, so the parse infrastructure does not enforce a minimum length for the event struct. Additionally, the num_vdevs field is taken directly from firmware and used as a loop bound over the vdev_ids array without checking that it fits within the TLV payload. Either condition can cause an out-of-bounds read. Add a TLV policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT so the parse infrastructure enforces a minimum length for the fixed-size event struct. Add a helper ath12k_wmi_tlv_data_len() to recover the payload length of a parsed TLV from the header preceding its data pointer. Use it in ath12k_wmi_process_csa_switch_count_event() to bound num_vdevs before the loop. Compile tested only.

Affected products

Linux kernel: 6.3 — fixed in 7.3

How to fix

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

References

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