CVE-2025-38245

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

atm: Release atm_dev_mutex after removing procfs in atm_dev_deregister().

syzbot reported a warning below during atm_dev_register(). [0]

Before creating a new device and procfs/sysfs for it, atm_dev_register()

looks up a duplicated device by __atm_dev_lookup(). These operations are

done under atm_dev_mutex.

However, when removing a device in atm_dev_deregister(), it releases the

mutex just after removing the device from the list that __atm_dev_lookup()

iterates over.

So, there will be a small race window where the device does not exist on

the device list but procfs/sysfs are still not removed, triggering the

splat.

Let's hold the mutex until procfs/sysfs are removed in

atm_dev_deregister().

[0]:

proc_dir_entry 'atm/atmtcp:0' already registered

WARNING: CPU: 0 PID: 5919 at fs/proc/generic.c:377 proc_register+0x455/0x5f0 fs/proc/generic.c:377

Modules linked in:

CPU: 0 UID: 0 PID: 5919 Comm: syz-executor284 Not ta

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References