CVE-2025-68173 ftrace: Fix softlockup in ftrace_module_enable
A local attacker can cause a kernel panic and system denial of service by loading a kernel module with many traceable functions.
- 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-2025-68173?
CVE-2025-68173 is a denial of service vulnerability in Linux, published on 16 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:
ftrace: Fix softlockup in ftrace_module_enable
A soft lockup was observed when loading amdgpu module. If a module has a lot of tracable functions, multiple calls to kallsyms_lookup can spend too much time in RCU critical section and with disabled preemption, causing kernel panic. This is the same issue that was fixed in commit d0b24b4e91fc ("ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY kernels") and commit 42ea22e754ba ("ftrace: Add cond_resched() to ftrace_graph_set_hash()").
Fix it the same way by adding cond_resched() in ftrace_module_enable.
Which versions are affected by CVE-2025-68173?
How do I fix CVE-2025-68173?
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-2025-68173 being exploited?
There is no known exploitation of CVE-2025-68173 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68173, DEBIAN-CVE-2025-68173, GHSA-6j5g-jv8m-99rc, ROOT-OS-DEBIAN-11-CVE-2025-68173, ROOT-OS-DEBIAN-12-CVE-2025-68173, ROOT-OS-DEBIAN-13-CVE-2025-68173 and 3 more.