wifi: wcn36xx: fix OOB read from short trigger BA firmware response

[ Upstream commit b5e6f21 ]

The firmware response length is only checked against sizeof(*rsp) (20
bytes), but when candidate_cnt >= 1, a 22-byte candidate struct is read
at buf + 20 without verifying the response contains it. This causes an
out-of-bounds read of stale heap data, corrupting the BA session state.

Add validation that the response includes the candidate data.

Fixes: 16be1ac ("wcn36xx: Parse trigger_ba response properly")
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Reviewed-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Link: https://patch.msgid.link/20260421135018.352774-4-tristmd@gmail.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Tristan Madani

drivers/net/wireless/ath/wcn36xx/smd.c

@@ -2659,6 +2659,9 @@ static int wcn36xx_smd_trigger_ba_rsp(void *buf, int len, struct add_ba_info *ba
 	if (rsp->candidate_cnt < 1)
 		return rsp->status ? rsp->status : -EINVAL;
 
+	if (len < sizeof(*rsp) + sizeof(*candidate))
+		return -EINVAL;
+
 	candidate = (struct wcn36xx_hal_trigger_ba_rsp_candidate *)(buf + sizeof(*rsp));
 
 	for (i = 0; i < STACFG_MAX_TC; i++) {