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The vulnerability CVE-2025-37967 is a deadlock condition within the Linux kernel’s USB Type-C Connector System Software Interface (UCSI) driver, specifically affecting DisplayPort alternate mode functionality. This deadlock occurs due to improper mutex (mutual exclusion) locking between two key functions. The function `ucsi_displayport_remove_partner` acquires and holds the connector mutex (con->mutex) while it waits for a work item named `dp_altmode_work` to finish its execution. Simultaneously, the `dp_altmode_work` function itself attempts to acquire the same `con->mutex` lock before it can proceed. Since the mutex is already held by the first function, `dp_altmode_work` cannot continue, but its completion is required for `ucsi_displayport_remove_partner` to release the lock. This circular dependency results in a permanent software deadlock. The kernel patch resolves this by introducing new wrapper functions, `ucsi_con_mutex_lock` and ucsi_con_mutex_unlock. The core fix in `ucsi_con_mutex_lock` is to add a safety check before locking the mutex; it ensures that the connector’s partner pointer is valid and a connection is truly established, thereby preventing the deadlock scenario from being initiated under invalid states.
dailycve form
Platform: Linux Kernel
Version: 5.2 to 6.15-rc5
Vulnerability: Mutex Deadlock
Severity: Medium
date: May 20, 2025
Prediction: May 24, 2025
What Undercode Say:
Analytics
- CVSS Score: 5.5
- Vector: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CWE ID: 667 (Improper Locking)
- EPSS Probability: 0.06%
Bash Commands and Codes
Check current kernel version uname -r Check for available security updates (Debian/Ubuntu) sudo apt update && sudo apt list --upgradable | grep linux-image Update kernel packages (Debian/Ubuntu) sudo apt upgrade linux-image- Check fixed kernel versions for SLES kernel-default >= 6.4.0-150600.23.60.5
How Exploit:
- Required Access: Local
- Complexity: Low
- Method: Trigger USB-C DisplayPort partner removal sequence.
- Result: Kernel thread deadlock, Denial of Service.
Protection from this CVE
- Apply kernel update.
- Patch introduces
ucsi_con_mutex_lock. - Validate partner pointer before locking.
Impact:
- Availability Impact: High.
- Consequence: System instability, resource freeze.
- Scope: Local, Unchanged.
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Sources:
Reported By: nvd.nist.gov
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