CVE-2025-38424 perf: Fix sample vs do_exit()
A race condition in the Linux kernel perf subsystem allows a local attacker to cause a system crash by triggering a use-after-free during process exit.
- 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-2025-38424?
CVE-2025-38424 is a high-severity vulnerability in Debian Debian Linux, published on 25 Jul 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:
perf: Fix sample vs do_exit()
Baisheng Gao reported an ARM64 crash, which Mark decoded as being a synchronous external abort -- most likely due to trying to access MMIO in bad ways.
The crash further shows perf trying to do a user stack sample while in exit_mmap()'s tlb_finish_mmu() -- i.e. while tearing down the address space it is trying to access.
It turns out that we stop perf after we tear down the userspace mm; a receipie for disaster, since perf likes to access userspace for various reasons.
Flip this order by moving up where we stop perf in do_exit().
Additionally, harden PERF_SAMPLE_CALLCHAIN and PERF_SAMPLE_STACK_USER to abort when the current task does not have an mm (exit_mm() makes sure to set current->mm = NULL; before commencing with the actual teardown). Such that CPU wide events don't trip on this same problem.
Which versions are affected by CVE-2025-38424?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38424?
Apply the vendor's patch.
Is CVE-2025-38424 being exploited?
There is no known exploitation of CVE-2025-38424 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2025-38424, DEBIAN-CVE-2025-38424, GHSA-6p9w-8r99-f39c, OESA-2025-1962, ROOT-OS-DEBIAN-11-CVE-2025-38424, ROOT-OS-DEBIAN-12-CVE-2025-38424 and 3 more.