CVE-2023-54036

CVE-2023-54036 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

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.

Frequently asked questions

What is CVE-2023-54036?
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.
Is CVE-2023-54036 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2023-54036?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2023-54036 have an EU (EUVD) identifier?
Yes. CVE-2023-54036 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-205126.
When was CVE-2023-54036 published?
CVE-2023-54036 was published on 2025-12-24 and last updated on 2026-06-17.

References