{"id":"CVE-2026-64175","summary":"wifi: iwlwifi: mld: stop TX during firmware restart","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's 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.","modified":"2026-07-22T03:31:42.474313357Z","published":"2026-07-19T15:41:00.157Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64175.json"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64175.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64175"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d1e879ec600f9b3bdd253167533959facfefb17b"},{"fixed":"dc31c69476520bb4c2a208211a8d3c310a62c4d0"},{"fixed":"13f1786395dbbf3df73337063c798f1266be6151"},{"fixed":"2becb38a3e217ef2b2f42fddd7db7a25905ec291"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64175.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.15.0"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64175.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}