Look up another CVE · open CVE-2026-90398 in the interactive tracker
CVE-2026-90398
wifi: ath11k: fix stride mismatch in mac_phy_caps_parse()
Published 2026-09-17 (31 days ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-90398 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
Currently, in ath11k_wmi_tlv_mac_phy_caps_parse(), kcalloc() sizes the mac_phy_caps buffer as tot_phy_id * len, where len is clamped to min(firmware_len, sizeof(struct wmi_mac_phy_capabilities)). The subsequent memcpy() destination advances by sizeof(full struct) per slot via C pointer arithmetic, not by the clamped len. When firmware sends short TLVs, the second and later slots are written past the end of the allocation. The reader in ath11k_pull_mac_phy_cap_svc_ready_ext() also indexes the buffer with full-struct pointer arithmetic, so the allocation must match that stride. Fix by using kzalloc_objs(), which derives the element size from the pointer type, making allocation size and pointer stride provably consistent regardless of what len the firmware provides. Compile tested only.
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/ath/ath11k/wmi.c
- What this is
- QUALCOMM ATHEROS ATH11K WIRELESS DRIVERMAINTAINERS section matched on drivers/net/wireless/ath/ath11k/ · linux-wireless@vger.kernel.org · Supported
- Kernel module
- ath11k
Check it on the machine
grep -wE 'CONFIG_ATH11K|CONFIG_WLAN|CONFIG_WLAN_VENDOR_ATH' /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.
lsmod | grep -w ath11kPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_ATH11K, CONFIG_WLAN, CONFIG_WLAN_VENDOR_ATH
- 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
- 2026-09-17 (31 days ago)source
- CVSS
- 8.4 high
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.14%, higher than 3.1% 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 |
|---|---|---|
| 5.6 | 6.12.110 | bbb3b3334a9e |
| 5.6 | 6.18.52 | 75185e2b214e |
| 5.6 | 7.2.6 | acff2713c321 |
| 5.6 | 7.3 | 7a246c72132e |
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:LAttack vector, local
- The short WMI_TAG_MAC_PHY_CAPABILITIES lengths that undersize kcalloc() arrive in WMI_SERVICE_READY_EXT_EVENTID on the target-to-host WMI Copy Engine (CE2 → ath11k_ce_recv_process_cb → ath11k_htc_rx_completion_handler → ath11k_wmi_tlv_op_rx), a host-firmware HTC path, not over-the-air 802.11 frames.
- AC:LAttack complexity, low
- wmi_tlv_policies has no min_len for WMI_TAG_MAC_PHY_CAPABILITIES, and tot_phy_id is the firmware phy_id_map shift-count from ath11k_wmi_tlv_hw_mode_caps_parse(); a SERVICE_READY_EXT with tot_phy_id>=2 and TLV len < sizeof(struct wmi_mac_phy_capabilities) makes the memcpy() past the allocation deterministic, with no race.
- PR:NPrivileges required, none
- ath11k_service_ready_ext_event() runs from the WMI HTC rx callback during ath11k_core_start() with no capability, credential, or host authentication check; the device firmware is the sole source of the MAC_PHY_CAPABILITIES TLVs.
- UI:NUser interaction, none
- ath11k_wmi_wait_for_service_ready() in ath11k_core_start() consumes SERVICE_READY_EXT on probe and again from ath11k_core_reconfigure_on_crash(); no victim action such as mounting a volume or opening a file is required.
- S:UScope, unchanged
- The overflowed memcpy() corrupts the GFP_ATOMIC mac_phy_caps heap object inside the host kernel's ath11k WMI parser and does not cross a VM, IOMMU, or other separate security authority.
- C:HConfidentiality impact, high
- Firmware-chosen bytes are written past the tot_phy_id*len kcalloc() at sizeof(struct wmi_mac_phy_capabilities) strides (~232 bytes), which is heap memory corruption that can be leveraged for arbitrary disclosure.
- I:HIntegrity impact, high
- Each overflowed memcpy() in ath11k_wmi_tlv_mac_phy_caps_parse() stores firmware-chosen TLV payload past the mac_phy_caps heap object, an out-of-bounds kernel write of attacker-controlled length and contents.
- A:HAvailability impact, high
- The same heap overflow of mac_phy_caps, and later full-struct indexing in ath11k_pull_mac_phy_cap_svc_ready_ext(), can oops or panic the kernel.