From a31b0e535fd11219556c7382ee9f63b2438c3769 Mon Sep 17 00:00:00 2001 From: Shahar Tzarfati Date: Wed, 15 Jul 2026 21:57:05 +0300 Subject: [PATCH] wifi: iwlwifi: fw: validate SMEM response size The SMEM parsers cast firmware response payloads directly to shared memory configuration structures. A short response can leave fields outside the received payload while the driver still dereferences them. Check the response payload length before reading the base fields in both parser variants. Require the full legacy extended layout before reading internal TX FIFO data. Valid responses keep the same parsed values. Signed-off-by: Shahar Tzarfati Reviewed-by: Johannes Berg Signed-off-by: Miri Korenblit Link: https://patch.msgid.link/20260715215523.fbdb0016a91d.I5f6c6e04589a24a233559191170ccb43372dee63@changeid --- drivers/net/wireless/intel/iwlwifi/fw/smem.c | 28 ++++++++++++++++---- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/fw/smem.c b/drivers/net/wireless/intel/iwlwifi/fw/smem.c index 344ddde85b18..20ed26a1bb00 100644 --- a/drivers/net/wireless/intel/iwlwifi/fw/smem.c +++ b/drivers/net/wireless/intel/iwlwifi/fw/smem.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* - * Copyright (C) 2012-2014, 2018-2021, 2025 Intel Corporation + * Copyright (C) 2012-2014, 2018-2021, 2025-2026 Intel Corporation * Copyright (C) 2013-2015 Intel Mobile Communications GmbH * Copyright (C) 2016-2017 Intel Deutschland GmbH */ @@ -14,9 +14,17 @@ static void iwl_parse_shared_mem_22000(struct iwl_fw_runtime *fwrt, { struct iwl_shared_mem_cfg *mem_cfg = (void *)pkt->data; int i, lmac; - int lmac_num = le32_to_cpu(mem_cfg->lmac_num); - u8 api_ver = iwl_fw_lookup_notif_ver(fwrt->fw, SYSTEM_GROUP, - SHARED_MEM_CFG_CMD, 0); + int lmac_num; + u8 api_ver; + + if (IWL_FW_CHECK(fwrt, iwl_rx_packet_payload_len(pkt) < + offsetofend(struct iwl_shared_mem_cfg, lmac_smem[1]), + "bad shared mem notification size\n")) + return; + + lmac_num = le32_to_cpu(mem_cfg->lmac_num); + api_ver = iwl_fw_lookup_notif_ver(fwrt->fw, SYSTEM_GROUP, + SHARED_MEM_CFG_CMD, 0); /* Note: notification has 3 entries, but we only expect 2 */ if (IWL_FW_CHECK(fwrt, lmac_num > ARRAY_SIZE(fwrt->smem_cfg.lmac), @@ -30,7 +38,7 @@ static void iwl_parse_shared_mem_22000(struct iwl_fw_runtime *fwrt, if (api_ver >= 4 && !IWL_FW_CHECK(fwrt, iwl_rx_packet_payload_len(pkt) < sizeof(*mem_cfg), - "bad shared mem notification size\n")) { + "bad shared mem notification size (v4)\n")) { fwrt->smem_cfg.rxfifo2_control_size = le32_to_cpu(mem_cfg->rxfifo2_control_size); } @@ -53,6 +61,11 @@ static void iwl_parse_shared_mem(struct iwl_fw_runtime *fwrt, struct iwl_shared_mem_cfg_v2 *mem_cfg = (void *)pkt->data; int i; + if (IWL_FW_CHECK(fwrt, iwl_rx_packet_payload_len(pkt) < + offsetof(struct iwl_shared_mem_cfg_v2, rxfifo_addr), + "bad shared mem notification size\n")) + return; + fwrt->smem_cfg.num_lmacs = 1; fwrt->smem_cfg.num_txfifo_entries = ARRAY_SIZE(mem_cfg->txfifo_size); @@ -67,6 +80,11 @@ static void iwl_parse_shared_mem(struct iwl_fw_runtime *fwrt, /* new API has more data, from rxfifo_addr field and on */ if (fw_has_capa(&fwrt->fw->ucode_capa, IWL_UCODE_TLV_CAPA_EXTEND_SHARED_MEM_CFG)) { + if (IWL_FW_CHECK(fwrt, iwl_rx_packet_payload_len(pkt) < + sizeof(*mem_cfg), + "bad shared mem notification size (extend)\n")) + return; + BUILD_BUG_ON(sizeof(fwrt->smem_cfg.internal_txfifo_size) != sizeof(mem_cfg->internal_txfifo_size));