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CVE-2026-68353
wifi: ath6kl: fix OOB read from firmware num_msg in TX complete handler
Published 2026-08-10 (2 months 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-2026-68353 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 | fixedDLA-4777-1 · 2026-09-08 · text | 6.1.187-1 | Update the kernel and reboot. DLA-4777-1 shipped the fix on 2026-09-08, in 6.1.187-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.101-1 | Update the kernel and reboot. Fixed in 6.12.101-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4745-1 · 2026-08-18 · text | 6.12.101-1~deb12u1 | Update the kernel and reboot. DLA-4745-1 shipped the fix on 2026-08-18, in 6.12.101-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The firmware-controlled num_msg field (u8, 0-255) drives the loop in ath6kl_wmi_tx_complete_event_rx() without validation against the buffer length. This allows out-of-bounds reads of up to 1020 bytes past the WMI event buffer when the firmware sends an inflated num_msg. Add a check that the buffer is large enough to hold the fixed struct and the num_msg variable-length entries.
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/ath6kl/wmi.c
- What this is
- ATHEROS ATH6KL WIRELESS DRIVERMAINTAINERS section matched on drivers/net/wireless/ath/ath6kl/ · linux-wireless@vger.kernel.org · Orphan
- Kernel module
- ath6kl_core
Check it on the machine
grep -wE 'CONFIG_ATH6KL|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 ath6kl_corePrints 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_ATH6KL, 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
- 2026-08-10 (2 months ago)source
- CVSS
- 8.1 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.29%, higher than 19.8% 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 |
|---|---|---|
| 3.2 | 5.10.265 | 5297299c3fa6 |
| 3.2 | 5.15.216 | 35196a07603f |
| 3.2 | 6.1.183 | 0e0fc04af9b4 |
| 3.2 | 6.6.148 | 69ac7ba3a3df |
| 3.2 | 6.12.101 | 289edc3c7134 |
| 3.2 | 6.18.42 | eb636fbc4431 |
| 3.2 | 7.1.6 | c38b0d5c6619 |
| 3.2 | 7.2 | 3a21c89215cc |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4777-1 | 2026-09-08 | bookworm 6.1.187-1 | tracker |
| DLA-4745-1 | 2026-08-18 | bookworm 6.12.101-1~deb12u1 | 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
- The vulnerable handler parses WMI control events delivered by the ath6kl AR600x wireless firmware over SDIO/USB; an attacker on the same wireless segment who subverts or influences the wireless device's firmware supplies the malformed event, matching the adjacent-network vector used for other ath driver event-parsing flaws.
- AC:LAttack complexity, low
- Triggering requires only a WMI_TX_COMPLETE_EVENTID event whose payload is shorter than num_msg * 4 bytes; the loop bound is taken directly from the event with no validation, so the read happens deterministically every time.
- PR:NPrivileges required, none
- The event is processed in the driver's asynchronous control-message receive path with no capability check, no syscall entry, and no authentication or association gate; the attacker needs no credentials on the target system.
- UI:NUser interaction, none
- The WMI event is handled automatically by the driver as soon as the interface is running; no victim action such as opening a file or issuing a command is needed.
- S:UScope, unchanged
- The out-of-bounds read stays within the kernel's own memory and security authority; no VM, IOMMU, or sandbox boundary is crossed.
- C:HConfidentiality impact, high
- Up to 1020 bytes past the event buffer are read and the contents are emitted through ath6kl_dbg() into the kernel log on debug builds, disclosing adjacent kernel heap data well beyond a small bounded read.
- I:NIntegrity impact, none
- The loop only reads and prints the out-of-bounds entries; there is no write to kernel memory and no attacker-controlled pointer is dereferenced for modification.
- A:HAvailability impact, high
- The read can walk past the end of the slab allocation into unmapped or redzoned memory, producing an oops or a KASAN panic on hardened/debug kernels and thus a full loss of availability.