CVE-2025-38262 tty: serial: uartlite: register uart driver in init
A race condition in the Linux kernel's uartlite driver can cause a null pointer dereference and kernel panic during device probing.
- 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-2025-38262?
CVE-2025-38262 is a high-severity vulnerability in Debian Debian Linux, published on 9 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:
tty: serial: uartlite: register uart driver in init
When two instances of uart devices are probing, a concurrency race can occur. If one thread calls uart_register_driver function, which first allocates and assigns memory to 'uart_state' member of uart_driver structure, the other instance can bypass uart driver registration and call ulite_assign. This calls uart_add_one_port, which expects the uart driver to be fully initialized. This leads to a kernel panic due to a null pointer dereference:
[ 8.143581] BUG: kernel NULL pointer dereference, address: 00000000000002b8 [ 8.156982] #PF: supervisor write access in kernel mode [ 8.156984] #PF: error_code(0x0002) - not-present page [ 8.156986] PGD 0 P4D 0 ... [ 8.180668] RIP: 0010:mutex_lock+0x19/0x30 [ 8.188624] Call Trace: [ 8.188629] ? __die_body.cold+0x1a/0x1f [ 8.195260] ? page_fault_oops+0x15c/0x290 [ 8.209183] ? __irq_resolve_mapping+0x47/0x80 [ 8.209187] ? exc_page_fault+0x64/0x140 [ 8.209190] ? asm_exc_page_fault+0x22/0x30 [ 8.209196] ? mutex_lock+0x19/0x30 [ 8.223116] uart_add_one_port+0x60/0x440 [ 8.223122] ? proc_tty_register_driver+0x43/0x50 [ 8.223126] ? tty_register_driver+0x1ca/0x1e0 [ 8.246250] ulite_probe+0x357/0x4b0 [uartlite]
To prevent it, move uart driver registration in to init function. This will ensure that uart_driver is always registered when probe function is called.
Weakness: CWE-476
Which versions are affected by CVE-2025-38262?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38262?
Apply the vendor's patch.
Is CVE-2025-38262 being exploited?
There is no known exploitation of CVE-2025-38262 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-64853, AZL-72799, BELL-CVE-2025-38262, DEBIAN-CVE-2025-38262, GHSA-hx36-fpq9-j3mg, ROOT-OS-DEBIAN-11-CVE-2025-38262 and 4 more.