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

Official 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 packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/d4aec20f3a84634171c139ab2e02bb2e5a5c756b
• https://git.kernel.org/stable/c/24f7cdabea9f7ab95dbd6d8bc9ac6ec48d96a7e5
• https://git.kernel.org/stable/c/23bed4ef132c55c9016f0c6122c8b8ba2efa2353
• https://git.kernel.org/stable/c/bf97c9d5123859a07848462539153176db029f3a
• https://git.kernel.org/stable/c/878654eb78c6aa0ff585baf1376567c775ca28ec