CVE-2026-90399wifi: ath12k: fix stride mismatch in mac_phy_caps_parse()

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix stride mismatch in mac_phy_caps_parse() Currently, in ath12k_wmi_mac_phy_caps_parse(), kzalloc() sizes the mac_phy_caps buffer as tot_phy_id * len, where len is clamped to min(firmware_len, sizeof(struct ath12k_wmi_mac_phy_caps_params)). The subsequent memcpy() destination advances by sizeof(full struct) per slot via C pointer arithmetic, not by the clamped len. When firmware sends short TLVs, the second and later slots are written past the end of the allocation. The reader in ath12k_pull_mac_phy_cap_svc_ready_ext() also indexes the buffer with full-struct pointer arithmetic, so the allocation must match that stride. Fix by using kzalloc_objs(), which derives the element size from the pointer type, making allocation size and pointer stride provably consistent regardless of what len the firmware provides. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/79c6f4f7d16eea1bcb8bc5c8fd6ec04a01b0614f
• https://git.kernel.org/stable/c/d3355e0fdbbf531ca8b82a6a3feb80a1b7306a8b
• https://git.kernel.org/stable/c/b9a5d12cbdeb860306f8d47c92caee0ea6ee0e0a
• https://git.kernel.org/stable/c/26f8f87f0a556e7984366c64cebc16d49e15d22f
• https://git.kernel.org/stable/c/4c6eb712a91fa079be6f9f1419c96e0ad2227081