CVE-2023-54036 wifi: rtl8xxxu: Fix memory leaks with RTL8723BU, RTL8192EU
A memory leak in the Linux kernel rtl8xxxu WiFi driver allows attackers to cause denial of service via Bluetooth traffic or rate changes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54036?
CVE-2023-54036 is a memory corruption vulnerability in Linux, published on 24 Dec 2025. 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: rtl8xxxu: Fix memory leaks with RTL8723BU, RTL8192EU
The wifi + bluetooth combo chip RTL8723BU can leak memory (especially?) when it's connected to a bluetooth audio device. The busy bluetooth traffic generates lots of C2H (card to host) messages, which are not freed correctly.
To fix this, move the dev_kfree_skb() call in rtl8xxxu_c2hcmd_callback() inside the loop where skb_dequeue() is called.
The RTL8192EU leaks memory because the C2H messages are added to the queue and left there forever. (This was fine in the past because it probably wasn't sending any C2H messages until commit e542e66b7c2e ("wifi: rtl8xxxu: gen2: Turn on the rate control"). Since that commit it sends a C2H message when the TX rate changes.)
To fix this, delete the check for rf_paths > 1 and the goto. Let the function process the C2H messages from RTL8192EU like the ones from the other chips.
Theoretically the RTL8188FU could also leak like RTL8723BU, but it most likely doesn't send C2H messages frequently enough.
This change was tested with RTL8723BU by Erhard F. I tested it with RTL8188FU and RTL8192EU.
Which versions are affected by CVE-2023-54036?
How do I fix CVE-2023-54036?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-54036 being exploited?
There is no known exploitation of CVE-2023-54036 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54036, DEBIAN-CVE-2023-54036, GHSA-j3w7-7qhh-rrr2, UBUNTU-CVE-2023-54036.