CVE-2025-39752 ARM: rockchip: fix kernel hang during smp initialization
A race condition during SMP initialization on Rockchip ARM devices can cause the Linux kernel to hang, resulting in 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-2025-39752?
CVE-2025-39752 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 11 Sep 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:
ARM: rockchip: fix kernel hang during smp initialization
In order to bring up secondary CPUs main CPU write trampoline code to SRAM. The trampoline code is written while secondary CPUs are powered on (at least that true for RK3188 CPU). Sometimes that leads to kernel hang. Probably because secondary CPU execute trampoline code while kernel doesn't expect.
The patch moves SRAM initialization step to the point where all secondary CPUs are powered down.
That fixes rarely hangs on RK3188: [ 0.091568] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000 [ 0.091996] rockchip_smp_prepare_cpus: ncores 4
Which versions are affected by CVE-2025-39752?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-39752?
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-2025-39752 being exploited?
There is no known exploitation of CVE-2025-39752 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-67214, AZL-73950, BELL-CVE-2025-39752, DEBIAN-CVE-2025-39752, GHSA-pr7q-phhw-mf48, ROOT-OS-DEBIAN-11-CVE-2025-39752 and 4 more.