CVE-2024-26897 wifi: ath9k: delay all of ath9k_wmi_event_tasklet() until init is complete
A race condition in the ath9k WiFi driver allows a local attacker to trigger a null pointer dereference, causing a system crash.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-26897?
CVE-2024-26897 is a medium-severity vulnerability in Debian Debian Linux, published on 17 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k: delay all of ath9k_wmi_event_tasklet() until init is complete
The ath9k_wmi_event_tasklet() used in ath9k_htc assumes that all the data structures have been fully initialised by the time it runs. However, because of the order in which things are initialised, this is not guaranteed to be the case, because the device is exposed to the USB subsystem before the ath9k driver initialisation is completed.
We already committed a partial fix for this in commit: 8b3046abc99e ("ath9k_htc: fix NULL pointer dereference at ath9k_htc_tx_get_packet()")
However, that commit only aborted the WMI_TXSTATUS_EVENTID command in the event tasklet, pairing it with an "initialisation complete" bit in the TX struct. It seems syzbot managed to trigger the race for one of the other commands as well, so let's just move the existing synchronisation bit to cover the whole tasklet (setting it at the end of ath9k_htc_probe_device() instead of inside ath9k_tx_init()).
Weakness: CWE-362
Which versions are affected by CVE-2024-26897?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2024-26897?
Apply the vendor's patch.
Is CVE-2024-26897 being exploited?
There is no known exploitation of CVE-2024-26897 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2024-26897, DEBIAN-CVE-2024-26897, GHSA-96gr-7mgw-2637, UBUNTU-CVE-2024-26897.