CVE-2025-38174 thunderbolt: Do not double dequeue a configuration request
A double dequeue bug in the Linux kernel Thunderbolt driver causes a general protection fault, leading to system crashes.
- 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-2025-38174?
CVE-2025-38174 is a high-severity use after free vulnerability in Debian Debian Linux, published on 4 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:
thunderbolt: Do not double dequeue a configuration request
Some of our devices crash in tb_cfg_request_dequeue():
general protection fault, probably for non-canonical address 0xdead000000000122
CPU: 6 PID: 91007 Comm: kworker/6:2 Tainted: G U W 6.6.65 RIP: 0010:tb_cfg_request_dequeue+0x2d/0xa0 Call Trace: <TASK> ? tb_cfg_request_dequeue+0x2d/0xa0 tb_cfg_request_work+0x33/0x80 worker_thread+0x386/0x8f0 kthread+0xed/0x110 ret_from_fork+0x38/0x50 ret_from_fork_asm+0x1b/0x30
The circumstances are unclear, however, the theory is that tb_cfg_request_work() can be scheduled twice for a request: first time via frame.callback from ring_work() and second time from tb_cfg_request(). Both times kworkers will execute tb_cfg_request_dequeue(), which results in double list_del() from the ctl->request_queue (the list poison deference hints at it: 0xdead000000000122).
Do not dequeue requests that don't have TB_CFG_REQUEST_ACTIVE bit set.
Which versions are affected by CVE-2025-38174?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38174?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-38174 being exploited?
There is no known exploitation of CVE-2025-38174 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-64647, BELL-CVE-2025-38174, DEBIAN-CVE-2025-38174, GHSA-vpp5-35pq-5g47, ROOT-OS-DEBIAN-11-CVE-2025-38174, ROOT-OS-DEBIAN-12-CVE-2025-38174 and 3 more.