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CVE-2026-93790
wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif
Published 2026-09-24 (24 days ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: not yet assigned.
Debian does not build this code. The per-release build detail is under "Where it lives" below.
What to do, per Debian release
Debian's own status for CVE-2026-93790 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixedDSA-6528-1 · 2026-09-29 · text | 6.12.111-1 | Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4817-1 · 2026-10-04 · text | 6.12.111-1~deb12u1 | Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
mvmsta->tid_data was indexed by the TFD loop counter 'i' instead of the actual TID value 'tid'. This writes lq_color into a random tid_data slot unrelated to the BA entry. Since multi-TID blockack is not really in use, 'i' was always 0 and no harm was done. Add a out-of-bound check before accessing the array.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/net/wireless/intel/iwlwifi/mvm/tx.c
- What this is
- INTEL WIRELESS WIFI LINK (iwlwifi)MAINTAINERS section matched on drivers/net/wireless/intel/iwlwifi/ · linux-wireless@vger.kernel.org · Supported
- Kernel module
- none to look for. The file would have gone into iwlmvm, and Debian does not compile it into that module, so finding iwlmvm in lsmod would say nothing about this CVE.
Check it on the machine
grep -wE 'CONFIG_IWLMEI|CONFIG_IWLMVM|CONFIG_IWLWIFI|CONFIG_WLAN|CONFIG_WLAN_VENDOR_INTEL' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian does not build this code. In 5 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.
- bookworm, trixie, forky, sid, bookworm · linux-6.12n
- n
- not enabled on any flavour - this release does not build the code
- Build switches
- CONFIG_IWLMEI, CONFIG_IWLMVM, CONFIG_IWLWIFI, CONFIG_WLAN, CONFIG_WLAN_VENDOR_INTEL
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-09-24 (24 days ago)source
- CVSS
- 8.8 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.24%, higher than 14.2% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.15 | 6.6.158 | 35f991d685fe |
| 4.15 | 6.12.111 | c48b741277b0 |
| 4.15 | 6.18.53 | e8ac5e91b129 |
| 4.15 | 7.2 | 94d3982806c7 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4817-1 | 2026-10-04 | bookworm 6.12.111-1~deb12u1 | tracker |
| DSA-6528-1 | 2026-09-29 | trixie 6.12.111-1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:AAttack vector, adjacent network
- iwl_mvm_rx_ba_notif is the BA_NOTIF (0xc5) handler reached from iwl_pcie_rx_handle_rb → iwl_mvm_rx_mq → iwl_mvm_rx_common. The OOB index is tfd_cnt from iwl_compressed_ba_notif, firmware’s report of a received 802.11 Block Ack, so the triggering bytes arrive over WiFi radio range, not a routable IP protocol.
- AC:LAttack complexity, low
- On the new-TX-API path, iwl_mvm_rx_ba_notif writes mvmsta->tid_data[i].lq_color for i in [0, tfd_cnt) with no cap against ARRAY_SIZE(tid_data) (9). tfd_cnt is a firmware __le16 gated only by struct_size(..., tfd, tfd_cnt) versus pkt_len; a single BA_NOTIF with tfd_cnt>=10 is a deterministic sync-RX write, not a race.
- PR:NPrivileges required, none
- BA_NOTIF is RX_HANDLER_SYNC with no capable() or socket-cred check. iwl_mvm_sta_from_staid_rcu only needs sta_id to name a live fw_id_to_mac_id station (associated AP or client); the RF peer needs no host uid or capability.
- UI:NUser interaction, none
- iwl_mvm_rx_ba_notif runs from NAPI when firmware posts BA_NOTIF; the victim does not mount, open a file, or otherwise act to process the compressed BA once the WiFi interface already has a station.
- S:UScope, unchanged
- tid_data sits in iwl_mvm_sta inside ieee80211_sta->drv_priv; the overflow corrupts that host kernel object and adjacent heap, and does not cross a VM, IOMMU, or sandbox authority.
- C:HConfidentiality impact, high
- Each loop stores lq_color (TX_RES_RATE_TABLE_COL_GET of tlc_rate_info) at tid_data[i]; with tfd_cnt>=10 those 40-byte-strided writes leave the 9-element array, smash vif/ptk_pn, and continue into neighboring kernel objects, a memory-corruption disclosure primitive.
- I:HIntegrity impact, high
- The same store is a kernel OOB write: at i=9 the lq_color write lands on iwl_mvm_sta->vif, and larger tfd_cnt walks ptk_pn[] and off the station object, enabling pointer corruption and control-flow hijack rather than a bounded LQ-color update.
- A:HAvailability impact, high
- Corrupting vif or later heap pointers in iwl_mvm_sta makes the following iwl_mvm_tx_reclaim() (which reads mvmsta->vif and tid_data[tid]) and later station use oops; an unmapped-pointer dereference in RX softirq is a host kernel crash.