CVE-2021-47494 cfg80211: fix management registrations locking
A race condition in the Linux kernel's cfg80211 subsystem can cause list corruption, potentially leading to a 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-2021-47494?
CVE-2021-47494 is a high-severity vulnerability in Linux kernel, published on 22 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:
cfg80211: fix management registrations locking
The management registrations locking was broken, the list was locked for each wdev, but cfg80211_mgmt_registrations_update() iterated it without holding all the correct spinlocks, causing list corruption.
Rather than trying to fix it with fine-grained locking, just move the lock to the wiphy/rdev (still need the list on each wdev), we already need to hold the wdev lock to change it, so there's no contention on the lock in any case. This trivially fixes the bug since we hold one wdev's lock already, and now will hold the lock that protects all lists.
Weakness: CWE-667
Which versions are affected by CVE-2021-47494?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47494?
Apply the vendor's patch.
Is CVE-2021-47494 being exploited?
There is no known exploitation of CVE-2021-47494 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47494, GHSA-c6p9-mw2r-7mc4, UBUNTU-CVE-2021-47494.