From 92cee08dc4f00e77fd1317e4343c5d458b0abab7 Mon Sep 17 00:00:00 2001 From: Cole Leavitt Date: Sat, 4 Apr 2026 22:41:44 -0700 Subject: [PATCH 1/7] wifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled When the TLC notification disables AMSDU for a TID, the MLD driver sets max_tid_amsdu_len to the sentinel value 1. The TSO segmentation path in iwl_mld_tx_tso_segment() checks for zero but not for this sentinel, allowing it to reach the num_subframes calculation: num_subframes = (max_tid_amsdu_len + pad) / (subf_len + pad) = (1 + 2) / (1534 + 2) = 0 This zero propagates to iwl_tx_tso_segment() which sets: gso_size = num_subframes * mss = 0 Calling skb_gso_segment() with gso_size=0 creates over 32000 tiny segments from a single GSO skb. This floods the TX ring with ~1024 micro-frames (the rest are purged), creating a massive burst of TX completion events that can lead to memory corruption and a subsequent use-after-free in TCP's retransmit queue (refcount underflow in tcp_shifted_skb, NULL deref in tcp_rack_detect_loss). The MVM driver is immune because it checks mvmsta->amsdu_enabled before reaching the num_subframes calculation. The MLD driver has no equivalent bitmap check and relies solely on max_tid_amsdu_len, which does not catch the sentinel value. Fix this by detecting the sentinel value (max_tid_amsdu_len == 1) at the existing check and falling back to non-AMSDU TSO segmentation. Also add a WARN_ON_ONCE guard after the num_subframes division as defense-in-depth to catch any future code paths that produce zero through a different mechanism. Suggested-by: Miriam Rachel Korenblit Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") Signed-off-by: Cole Leavitt Link: https://patch.msgid.link/20260405054145.1064152-3-cole@unwrap.rs Signed-off-by: Miri Korenblit --- drivers/net/wireless/intel/iwlwifi/mld/tx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mld/tx.c b/drivers/net/wireless/intel/iwlwifi/mld/tx.c index 546d09a38dab..094a28f75559 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/tx.c @@ -834,7 +834,7 @@ static int iwl_mld_tx_tso_segment(struct iwl_mld *mld, struct sk_buff *skb, return -EINVAL; max_tid_amsdu_len = sta->cur->max_tid_amsdu_len[tid]; - if (!max_tid_amsdu_len) + if (!max_tid_amsdu_len || max_tid_amsdu_len == 1) return iwl_tx_tso_segment(skb, 1, netdev_flags, mpdus_skbs); /* Sub frame header + SNAP + IP header + TCP header + MSS */ @@ -846,6 +846,9 @@ static int iwl_mld_tx_tso_segment(struct iwl_mld *mld, struct sk_buff *skb, */ num_subframes = (max_tid_amsdu_len + pad) / (subf_len + pad); + if (WARN_ON_ONCE(!num_subframes)) + return iwl_tx_tso_segment(skb, 1, netdev_flags, mpdus_skbs); + if (sta->max_amsdu_subframes && num_subframes > sta->max_amsdu_subframes) num_subframes = sta->max_amsdu_subframes; From 2becb38a3e217ef2b2f42fddd7db7a25905ec291 Mon Sep 17 00:00:00 2001 From: Sheroz Juraev Date: Sun, 15 Mar 2026 13:12:21 +0500 Subject: [PATCH 2/7] wifi: iwlwifi: mld: stop TX during firmware restart When iwlwifi firmware crashes (e.g., NMI_INTERRUPT_UNKNOWN on Intel BE201/Wi-Fi 7), iwl_mld_nic_error() sets mld->fw_status.in_hw_restart to true. However, iwl_mld_tx_from_txq() does not check this flag before dequeuing frames from mac80211 and pushing them to the transport layer. Since the firmware is dead, iwl_trans_tx() returns -EIO for each frame, which then gets freed immediately. Under high-throughput conditions (e.g., Tailscale UDP traffic or active SSH sessions), this creates a tight dequeue-send-fail-free loop that wastes CPU cycles and generates rapid skb allocation churn, leading to memory pressure from slab fragmentation. The RX path already has this guard (iwl_mld_rx_mpdu checks in_hw_restart at rx.c:1906), and so does the TXQ allocation worker (iwl_mld_add_txqs_wk at tx.c:156). Add the same guard to iwl_mld_tx_from_txq() to stop all TX during firmware restart. Frames left in mac80211's TXQs are naturally drained after restart completes, when queue reallocation triggers iwl_mld_tx_from_txq() via iwl_mld_add_txq_list(), or when new upper-layer traffic invokes wake_tx_queue. Tested on ASUS Zenbook 14 UX3405CA with Intel BE201 (Wi-Fi 7) on kernel 6.19.5 where the firmware crashes approximately every 10-15 minutes under Tailscale traffic. Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") Cc: stable@vger.kernel.org Signed-off-by: Sheroz Juraev Link: https://patch.msgid.link/20260315081221.2678478-1-goodmartiandev@gmail.com Signed-off-by: Miri Korenblit --- drivers/net/wireless/intel/iwlwifi/mld/tx.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/net/wireless/intel/iwlwifi/mld/tx.c b/drivers/net/wireless/intel/iwlwifi/mld/tx.c index 094a28f75559..0bcb1ae69468 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/tx.c @@ -973,6 +973,16 @@ void iwl_mld_tx_from_txq(struct iwl_mld *mld, struct ieee80211_txq *txq) struct sk_buff *skb = NULL; u8 zero_addr[ETH_ALEN] = {}; + /* + * Don't transmit during firmware restart. The firmware is dead, + * so iwl_trans_tx() would return -EIO for each frame. Avoid the + * overhead of dequeuing from mac80211 only to immediately free + * the skbs, and the potential memory pressure from rapid skb + * allocation churn during high-throughput restart scenarios. + */ + if (unlikely(mld->fw_status.in_hw_restart)) + return; + /* * No need for threads to be pending here, they can leave the first * taker all the work. From d733ed481fd20a8e7bfe5119c4e77761ba3f87ee Mon Sep 17 00:00:00 2001 From: Miri Korenblit Date: Fri, 15 May 2026 15:14:56 +0300 Subject: [PATCH 3/7] wifi: iwlwifi: mld: don't dereference a pointer before NULL checking it In iwl_mld_remove_link, the link->fw_id is saved at the beginning of the function so we have it after we freed the link. But the link pointer can be NULL, and is not checked when the fw_id is stored. Fix it by simply freeing the link at the end of the function. fFixes: 0e66a39f4f0e ("wifi: iwlwifi: fix potential use after free in iwl_mld_remove_link()") Reviewed-by: Johannes Berg Link: https://patch.msgid.link/20260515151351.371f40fc6711.I6a82cfe9655564e9c5731af91c36493b26b1208e@changeid Signed-off-by: Miri Korenblit --- drivers/net/wireless/intel/iwlwifi/mld/link.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mld/link.c b/drivers/net/wireless/intel/iwlwifi/mld/link.c index b66e84d2365f..be2cdf43c72e 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/link.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/link.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* - * Copyright (C) 2024-2025 Intel Corporation + * Copyright (C) 2024-2026 Intel Corporation */ #include "constants.h" @@ -504,7 +504,6 @@ void iwl_mld_remove_link(struct iwl_mld *mld, struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(bss_conf->vif); struct iwl_mld_link *link = iwl_mld_link_from_mac80211(bss_conf); bool is_deflink = link == &mld_vif->deflink; - u8 fw_id = link->fw_id; if (WARN_ON(!link || link->active)) return; @@ -512,15 +511,15 @@ void iwl_mld_remove_link(struct iwl_mld *mld, iwl_mld_rm_link_from_fw(mld, bss_conf); /* Continue cleanup on failure */ - if (!is_deflink) - kfree_rcu(link, rcu_head); - RCU_INIT_POINTER(mld_vif->link[bss_conf->link_id], NULL); - if (WARN_ON(fw_id >= mld->fw->ucode_capa.num_links)) + if (WARN_ON(link->fw_id >= mld->fw->ucode_capa.num_links)) return; - RCU_INIT_POINTER(mld->fw_id_to_bss_conf[fw_id], NULL); + RCU_INIT_POINTER(mld->fw_id_to_bss_conf[link->fw_id], NULL); + + if (!is_deflink) + kfree_rcu(link, rcu_head); } void iwl_mld_handle_missed_beacon_notif(struct iwl_mld *mld, From fb84b5cbcaab3ca0f4e961d92a40ed7f3aac483b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 15 May 2026 15:14:57 +0300 Subject: [PATCH 4/7] wifi: iwlwifi: mvm: fix driver-set TX rates on old devices On old devices such as 7265D, rates are still encoded in version 1 format, which doesn't use the CCK/OFDM rate index (0-3/0-7) but rather their PLCP value (e.g. 10 for 1 Mbps CCK rate.) While introducing v3 rates, I changed the driver from internally handling v1 rates and converting to v2, to internally handling v3 and converting to v1 or v2 according to the firmware. I accordingly changed the code in iwl_mvm_mac80211_idx_to_hwrate() to no longer have different values for different APIs. This was correct. However, I later reverted this part of the change, because it was reported that I had broken beacon rates, causing a FW assert/crash. This caused TX_CMD rates to be set incorrectly, potentially causing a warning when reported back from the device as having been used. Fix this (hopefully correctly now) by handling beacon rates in the TX_CMD that's embedded in the beacon template command separately. Restore iwl_mvm_mac80211_idx_to_hwrate() to return only the rate index, not PLCP value, fixing the real TX_CMD. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg Link: https://patch.msgid.link/20260515151351.7407e293dff7.I4ea1a17f8fe99c933d3f3e30d077cf4246125c3e@changeid Signed-off-by: Miri Korenblit --- .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c | 27 ++++++++++++------- .../net/wireless/intel/iwlwifi/mvm/utils.c | 14 +++------- 2 files changed, 22 insertions(+), 19 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c index c523c5e82d4a..8ffa72aca3cf 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* - * Copyright (C) 2012-2014, 2018-2025 Intel Corporation + * Copyright (C) 2012-2014, 2018-2026 Intel Corporation * Copyright (C) 2013-2014 Intel Mobile Communications GmbH * Copyright (C) 2015-2017 Intel Deutschland GmbH */ @@ -927,13 +927,18 @@ u8 iwl_mvm_mac_ctxt_get_lowest_rate(struct iwl_mvm *mvm, u16 iwl_mvm_mac_ctxt_get_beacon_flags(const struct iwl_fw *fw, u8 rate_idx) { - u16 flags = iwl_mvm_mac80211_idx_to_hwrate(fw, rate_idx); bool is_new_rate = iwl_fw_lookup_cmd_ver(fw, BEACON_TEMPLATE_CMD, 0) > 10; + u16 flags = 0; if (rate_idx <= IWL_LAST_CCK_RATE) flags |= is_new_rate ? IWL_MAC_BEACON_CCK : IWL_MAC_BEACON_CCK_V1; + if (iwl_fw_lookup_cmd_ver(fw, TX_CMD, 0) > 8) + flags |= iwl_mvm_mac80211_idx_to_hwrate(fw, rate_idx); + else + flags |= iwl_fw_rate_idx_to_plcp(rate_idx); + return flags; } @@ -962,6 +967,7 @@ static void iwl_mvm_mac_ctxt_set_tx(struct iwl_mvm *mvm, { struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif); struct ieee80211_tx_info *info; + u32 rate_n_flags = 0; u8 rate; u32 tx_flags; @@ -981,18 +987,21 @@ static void iwl_mvm_mac_ctxt_set_tx(struct iwl_mvm *mvm, IWL_UCODE_TLV_CAPA_BEACON_ANT_SELECTION)) { iwl_mvm_toggle_tx_ant(mvm, &mvm->mgmt_last_antenna_idx); - tx_params->rate_n_flags = - cpu_to_le32(BIT(mvm->mgmt_last_antenna_idx) << - RATE_MCS_ANT_POS); + rate_n_flags |= BIT(mvm->mgmt_last_antenna_idx) << + RATE_MCS_ANT_POS; } rate = iwl_mvm_mac_ctxt_get_beacon_rate(mvm, info, vif); - tx_params->rate_n_flags |= - cpu_to_le32(iwl_mvm_mac80211_idx_to_hwrate(mvm->fw, rate)); - if (rate == IWL_FIRST_CCK_RATE) - tx_params->rate_n_flags |= cpu_to_le32(RATE_MCS_CCK_MSK_V1); + if (rate < IWL_FIRST_OFDM_RATE) + rate_n_flags |= RATE_MCS_MOD_TYPE_CCK; + else + rate_n_flags |= RATE_MCS_MOD_TYPE_LEGACY_OFDM; + rate_n_flags |= iwl_mvm_mac80211_idx_to_hwrate(mvm->fw, rate); + + tx_params->rate_n_flags = iwl_mvm_v3_rate_to_fw(rate_n_flags, + mvm->fw_rates_ver); } int iwl_mvm_mac_ctxt_send_beacon_cmd(struct iwl_mvm *mvm, diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c index 4a33a032c2a7..f052537e9567 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/utils.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/utils.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* - * Copyright (C) 2012-2014, 2018-2025 Intel Corporation + * Copyright (C) 2012-2014, 2018-2026 Intel Corporation * Copyright (C) 2013-2014 Intel Mobile Communications GmbH * Copyright (C) 2015-2017 Intel Deutschland GmbH */ @@ -159,15 +159,9 @@ int iwl_mvm_legacy_rate_to_mac80211_idx(u32 rate_n_flags, u8 iwl_mvm_mac80211_idx_to_hwrate(const struct iwl_fw *fw, int rate_idx) { - if (iwl_fw_lookup_cmd_ver(fw, TX_CMD, 0) > 8) - /* In the new rate legacy rates are indexed: - * 0 - 3 for CCK and 0 - 7 for OFDM. - */ - return (rate_idx >= IWL_FIRST_OFDM_RATE ? - rate_idx - IWL_FIRST_OFDM_RATE : - rate_idx); - - return iwl_fw_rate_idx_to_plcp(rate_idx); + return rate_idx >= IWL_FIRST_OFDM_RATE ? + rate_idx - IWL_FIRST_OFDM_RATE : + rate_idx; } u8 iwl_mvm_mac80211_ac_to_ucode_ac(enum ieee80211_ac_numbers ac) From 25e416f148f3f948638ca7c6ff63fd842d9c07ad Mon Sep 17 00:00:00 2001 From: Moriya Itzchaki Date: Fri, 15 May 2026 15:14:58 +0300 Subject: [PATCH 5/7] wifi: iwlwifi: use correct function to read STEP_URM register CNVI_PMU_STEP_FLOW is a PRPH register, not a UMAC PRPH register. Use iwl_read_prph() instead of iwl_read_umac_prph() to read it correctly. Signed-off-by: Moriya Itzchaki Reviewed-by: Johannes Berg Link: https://patch.msgid.link/20260515151352.3a69fa2dbda7.I8d96635a9c06a835b05a10b6d66c8a9299676246@changeid Signed-off-by: Miri Korenblit --- drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans-gen2.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans-gen2.c index a50e845cea42..64262bcca55d 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans-gen2.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/trans-gen2.c @@ -398,9 +398,9 @@ void iwl_trans_pcie_gen2_fw_alive(struct iwl_trans *trans) mutex_unlock(&trans_pcie->mutex); if (trans->mac_cfg->device_family >= IWL_DEVICE_FAMILY_BZ) - trans->step_urm = !!(iwl_read_umac_prph(trans, - CNVI_PMU_STEP_FLOW) & - CNVI_PMU_STEP_FLOW_FORCE_URM); + trans->step_urm = !!(iwl_read_prph(trans, + CNVI_PMU_STEP_FLOW) & + CNVI_PMU_STEP_FLOW_FORCE_URM); } static bool iwl_pcie_set_ltr(struct iwl_trans *trans) From b753b3334bad7c4735b6e5face0c331d4be11dda Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 15 May 2026 15:14:59 +0300 Subject: [PATCH 6/7] wifi: iwlwifi: mld: don't WARN on WoWLAN suspend w/o BSS vif Clearly, from a user perspective, it must be valid to configure WoWLAN (which can include network detection) and then suspend while not connected to a network, or even without an interface at all (WoWLAN config is handled on a per-wiphy basis). Since mac80211 doesn't distinguish these cases and simply calls the driver to suspend whenever WoWLAN is configured, the driver has to cleanly handle the case where it's called for WoWLAN but no (BSS) interface exists. Remove the WARN_ON(), move the print so it doesn't get done in this case, and keep returning 1 to disconnect everything. Signed-off-by: Johannes Berg Link: https://patch.msgid.link/20260515151352.0c55d1135409.I54f8be0e2aa28cfb1cb1dcf3b2d2d8fe75b4397b@changeid Signed-off-by: Miri Korenblit --- drivers/net/wireless/intel/iwlwifi/mld/d3.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mld/d3.c b/drivers/net/wireless/intel/iwlwifi/mld/d3.c index ef98efc8fb1b..3a595a1c2e00 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/d3.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/d3.c @@ -1930,12 +1930,12 @@ int iwl_mld_wowlan_suspend(struct iwl_mld *mld, struct cfg80211_wowlan *wowlan) if (WARN_ON(!wowlan)) return 1; - IWL_DEBUG_WOWLAN(mld, "Starting the wowlan suspend flow\n"); - bss_vif = iwl_mld_get_bss_vif(mld); - if (WARN_ON(!bss_vif)) + if (!bss_vif) return 1; + IWL_DEBUG_WOWLAN(mld, "Starting the wowlan suspend flow\n"); + if (!bss_vif->cfg.assoc) { int ret; /* If we're not associated, this must be netdetect */ From 734a4e051b9767f439137940095d63afbfed0745 Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Fri, 15 May 2026 15:15:00 +0300 Subject: [PATCH 7/7] wifi: iwlwifi: mld: disconnect only after 6 beacons without Rx After 4 missed beacons since last Rx, the firmware will send an NDP to the AP. If the NDP is ACK'ed, it'll reset the missed_beacons_since_last_rx counter. Disconnecting after 4 beacons doesn't give enough time to the firmware to send the NDP. Wait until we get 6 missed beacons since last Rx before disconnecting. Signed-off-by: Emmanuel Grumbach Link: https://patch.msgid.link/20260515151352.c4ed0d849f98.Iefa2e8be9edfc74683997eea60bb53c2002f31f0@changeid Signed-off-by: Miri Korenblit --- drivers/net/wireless/intel/iwlwifi/mld/constants.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mld/constants.h b/drivers/net/wireless/intel/iwlwifi/mld/constants.h index e2a5eecc18c3..890abcab3837 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/constants.h +++ b/drivers/net/wireless/intel/iwlwifi/mld/constants.h @@ -1,11 +1,11 @@ /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */ /* - * Copyright (C) 2024-2025 Intel Corporation + * Copyright (C) 2024-2026 Intel Corporation */ #ifndef __iwl_mld_constants_h__ #define __iwl_mld_constants_h__ -#define IWL_MLD_MISSED_BEACONS_SINCE_RX_THOLD 4 +#define IWL_MLD_MISSED_BEACONS_SINCE_RX_THOLD 6 #define IWL_MLD_MISSED_BEACONS_THRESHOLD 8 #define IWL_MLD_MISSED_BEACONS_THRESHOLD_LONG 19 #define IWL_MLD_BCN_LOSS_EXIT_ESR_THRESH_2_LINKS 5