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().

Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Link: https://patch.msgid.link/SYBPR01MB788115C6CE873271A9A15A25AF51A@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
This commit is contained in:
Junrui Luo 2026-04-02 14:48:07 +08:00 • committed by Miri Korenblit
commit f056fc2b92