CVE-2024-27391 wifi: wilc1000: do not realloc workqueue everytime an interface is added
Repeatedly adding and deleting WiFi interfaces causes workqueue resource leaks, potentially leading to system instability or denial of service.
- 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-2024-27391?
CVE-2024-27391 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 May 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: wilc1000: do not realloc workqueue everytime an interface is added
Commit 09ed8bfc5215 ("wilc1000: Rename workqueue from "WILC_wq" to "NETDEV-wq"") moved workqueue creation in wilc_netdev_ifc_init in order to set the interface name in the workqueue name. However, while the driver needs only one workqueue, the wilc_netdev_ifc_init is called each time we add an interface over a phy, which in turns overwrite the workqueue with a new one. This can be observed with the following commands:
for i in $(seq 0 10) do iw phy phy0 interface add wlan1 type managed iw dev wlan1 del done ps -eo pid,comm|grep wlan
39 kworker/R-wlan0 98 kworker/R-wlan1 102 kworker/R-wlan1 105 kworker/R-wlan1 108 kworker/R-wlan1 111 kworker/R-wlan1 114 kworker/R-wlan1 117 kworker/R-wlan1 120 kworker/R-wlan1 123 kworker/R-wlan1 126 kworker/R-wlan1 129 kworker/R-wlan1
Fix this leakage by putting back hif_workqueue allocation in wilc_cfg80211_init. Regarding the workqueue name, it is indeed relevant to set it lowercase, however it is not attached to a specific netdev, so enforcing netdev name in the name is not so relevant. Still, enrich the name with the wiphy name to make it clear which phy is using the workqueue.
Which versions are affected by CVE-2024-27391?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-27391?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-27391 being exploited?
There is no known exploitation of CVE-2024-27391 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-40325, BELL-CVE-2024-27391, DEBIAN-CVE-2024-27391, GHSA-g3jj-jjrf-q5mw, UBUNTU-CVE-2024-27391.