CVE-2026-90192 mailbox: qcom-cpucp: handle NULL data in send_data callback
A NULL pointer dereference in the Qualcomm CPUCP mailbox driver causes a kernel panic when clearing channels under PREEMPT_RT, leading to denial of service.
- 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-2026-90192?
CVE-2026-90192 is a vulnerability in Linux, published on 17 Sep 2026. 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:
mailbox: qcom-cpucp: handle NULL data in send_data callback
mailbox_clear_channel() calls mbox_send_message() with NULL data to notify the remote side that the RX channel has been cleared. qcom_cpucp_mbox_send_data() blindly dereferenced the data pointer, causing a NULL pointer dereference kernel panic when invoked from this path under PREEMPT_RT.
Add an explicit NULL check and return early without writing to the TX register, which is the correct behaviour for a channel-clear notification.
Which versions are affected by CVE-2026-90192?
How do I fix CVE-2026-90192?
Apply the vendor's patch.
Is CVE-2026-90192 being exploited?
There is no known exploitation of CVE-2026-90192 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90192, DEBIAN-CVE-2026-90192, GHSA-39h4-xrh5-39fg, UBUNTU-CVE-2026-90192.