Summary
In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Fix use-after...
In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Fix use-after-free in tb_dp_dprx_work
The original code relies on cancel_delayed_work() in tb_dp_dprx_stop(),
which does not ensure that the delayed work item tunnel->dprx_work has
fully completed if it was already running. This leads to use-after-free
scenarios where tb_tunnel is deallocated by tb_tunnel_put(), while
tunnel->dprx_work remains active and attempts to dereference tb_tunnel
in tb_dp_dprx_work().
A typical race condition is illustrated below:
CPU 0 | CPU 1
tb_dp_tunnel_active() |
tb_deactivate_and_free_tunnel()| tb_dp_dprx_start()
tb_tunnel_deactivate() | queue_delayed_work()
tb_dp_activate() |
tb_dp_dprx_stop() | tb_dp_dprx_work() //delayed worker
cancel_delayed_work() |
tb_tunnel_put(tunnel); |
| tunnel = container_of(...); //UAF
| tunnel-> //UAF
Replacing cancel_delayed_work() with cancel_delayed_work_sync() is
not feasible as it would introduce a deadlock: both tb_dp_dprx_work()
and the cleanup path acquire tb->lock, and cancel_delayed_work_sync()
would wait indefinitely for the work item that cannot proceed.
Instead, implement proper reference counting:
- If cancel_delayed_work() returns true (work is pending), we release
the reference in the stop function. - If it returns false (work is executing or already completed), the
reference is released in delayed work function itself.
This ensures the tb_tunnel remains valid during work item execution
while preventing memory leaks.
This bug was found by static analysis.
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-40002? CVE-2025-40002 is a unknown-severity security vulnerability. No fixed version is listed yet.
- Is there a fix for CVE-2025-40002? No fixed version is listed for CVE-2025-40002 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-40002 exploitable, and should I be worried? Whether CVE-2025-40002 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-40002 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.