wifi: ath11k: fix NULL dereference in ath11k_qmi_m3_load()

commit 3fd2ef2 upstream.

If ab->fw.m3_data points to data, then fw pointer remains null.
Further, if m3_mem is not allocated, then fw is dereferenced to be
passed to ath11k_err function.

Replace fw->size by m3_len.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 7db88b9 ("wifi: ath11k: add firmware-2.bin support")
Cc: stable@vger.kernel.org
Signed-off-by: Matvey Kovalev <matvey.kovalev@ispras.ru>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20250917192020.1340-1-matvey.kovalev@ispras.ru
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Matvey Kovalev

drivers/net/wireless/ath/ath11k/qmi.c

@@ -2550,7 +2550,7 @@ static int ath11k_qmi_m3_load(struct ath11k_base *ab)
 					   GFP_KERNEL);
 	if (!m3_mem->vaddr) {
 		ath11k_err(ab, "failed to allocate memory for M3 with size %zu\n",
-			   fw->size);
+			   m3_len);
 		ret = -ENOMEM;
 		goto out;
 	}