wifi: iwlwifi: yoyo: Fix possible division by zero

[ Upstream commit ba30415 ]

Don't allow buffer allocation TLV with zero req_size since it
leads later to division by zero in iwl_dbg_tlv_alloc_fragments().
Also, NPK/SRAM locations are allowed to have zero buffer req_size,
don't discard them.

Fixes: a9248de ("iwlwifi: dbg_ini: add TLV allocation new API support")
Signed-off-by: Daniel Gabay <daniel.gabay@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230413213309.5d6688ed74d8.I5c2f3a882b50698b708d54f4524dc5bdf11e3d32@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c

@@ -138,6 +138,12 @@ static int iwl_dbg_tlv_alloc_buf_alloc(struct iwl_trans *trans,
 	    alloc_id != IWL_FW_INI_ALLOCATION_ID_DBGC1)
 		goto err;
 
+	if (buf_location == IWL_FW_INI_LOCATION_DRAM_PATH &&
+	    alloc->req_size == 0) {
+		IWL_ERR(trans, "WRT: Invalid DRAM buffer allocation requested size (0)\n");
+		return -EINVAL;
+	}
+
 	trans->dbg.fw_mon_cfg[alloc_id] = *alloc;
 
 	return 0;