CVE-2025-38174

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.

This vulnerability presents a denial of service risk where race conditions during Thunderbolt configuration processing can result in memory corruption and a kernel crash. Exploiting this issue requires physical access to attach or manipulate Thunderbolt peripherals, substantially limiting exposure across enterprise server environments lacking these interfaces. Supported Red Hat Enterprise Linux releases are not affected because the vulnerable code structure is not present in their kernels.