GHSA-6WQH-XPRC-M65R
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:32In the Linux kernel, the following vulnerability has been resolved:
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.
{
"affected": [],
"aliases": [
"CVE-2026-64175"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:59Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: iwlwifi: mld: stop TX during firmware restart\n\nWhen iwlwifi firmware crashes (e.g., NMI_INTERRUPT_UNKNOWN on Intel\nBE201/Wi-Fi 7), iwl_mld_nic_error() sets mld-\u003efw_status.in_hw_restart\nto true. However, iwl_mld_tx_from_txq() does not check this flag before\ndequeuing frames from mac80211 and pushing them to the transport layer.\n\nSince the firmware is dead, iwl_trans_tx() returns -EIO for each frame,\nwhich then gets freed immediately. Under high-throughput conditions\n(e.g., Tailscale UDP traffic or active SSH sessions), this creates a\ntight dequeue-send-fail-free loop that wastes CPU cycles and generates\nrapid skb allocation churn, leading to memory pressure from slab\nfragmentation.\n\nThe RX path already has this guard (iwl_mld_rx_mpdu checks\nin_hw_restart at rx.c:1906), and so does the TXQ allocation worker\n(iwl_mld_add_txqs_wk at tx.c:156). Add the same guard to\niwl_mld_tx_from_txq() to stop all TX during firmware restart.\n\nFrames left in mac80211\u0027s TXQs are naturally drained after restart\ncompletes, when queue reallocation triggers iwl_mld_tx_from_txq()\nvia iwl_mld_add_txq_list(), or when new upper-layer traffic invokes\nwake_tx_queue.\n\nTested on ASUS Zenbook 14 UX3405CA with Intel BE201 (Wi-Fi 7) on\nkernel 6.19.5 where the firmware crashes approximately every 10-15\nminutes under Tailscale traffic.",
"id": "GHSA-6wqh-xprc-m65r",
"modified": "2026-07-20T15:32:02Z",
"published": "2026-07-19T18:31:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64175"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/13f1786395dbbf3df73337063c798f1266be6151"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2becb38a3e217ef2b2f42fddd7db7a25905ec291"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dc31c69476520bb4c2a208211a8d3c310a62c4d0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.