High · published July 24, 2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mld: validate sta_mask before ffs() in BA session handlers
Three BA session handlers use ffs(ba_data->sta_mask) - 1 to derive a
station ID without checking that sta_mask is non-zero. When sta_mask is
zero, ffs() returns 0 and the subtraction wraps to 0xFFFFFFFF, causing
an out-of-bounds access on fw_id_to_link_sta[].
Add WARN_ON_ONCE(!ba_data->sta_mask) guards before each ffs() call,
consistent with the existing check in iwl_mld_ampdu_rx_start().
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 6.4, < 6.18.38 | 6.18.38 |
| linux/linux_kernel | ≥ 6.19, < 7.1.3 | 7.1.3 |