CVE-2024-46868 in Linux
Summary
by MITRE • 09/27/2024
In the Linux kernel, the following vulnerability has been resolved:
firmware: qcom: uefisecapp: Fix deadlock in qcuefi_acquire()
If the __qcuefi pointer is not set, then in the original code, we would hold onto the lock. That means that if we tried to set it later, then it would cause a deadlock. Drop the lock on the error path. That's what all the callers are expecting.
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Analysis
by VulDB Data Team • 04/05/2026
The vulnerability identified as CVE-2024-46868 represents a critical deadlock condition within the Qualcomm UEFI Secure Application firmware handling subsystem of the Linux kernel. This issue specifically affects the qcuefi_acquire() function within the qcom firmware driver, where improper lock management creates a scenario that can halt system operations indefinitely. The flaw exists in the firmware loading and secure application execution pathway that is essential for proper system boot and security enforcement on Qualcomm-based platforms. The vulnerability impacts the kernel's ability to manage concurrent access to shared firmware resources, particularly when dealing with UEFI secure application initialization sequences.
The technical root cause of this vulnerability stems from improper lock release semantics within the firmware acquisition logic. When the __qcuefi pointer fails to initialize properly during the acquisition process, the code maintains an acquired lock while transitioning to an error handling path. This creates a circular dependency where subsequent attempts to acquire the same lock would block indefinitely, as the lock is never released from the error path. The original implementation fails to properly drop the lock before returning from error conditions, violating fundamental concurrency control principles. This pattern is particularly dangerous in kernel space where deadlocks can result in complete system hangs or kernel panics, affecting the entire boot process and system stability.
The operational impact of this vulnerability extends beyond simple system hangs to potentially compromise the entire boot sequence of Qualcomm-based devices. Systems relying on UEFI secure applications for firmware validation and secure boot processes become vulnerable to indefinite blocking during firmware initialization phases. Attackers could potentially exploit this condition to create persistent denial-of-service scenarios, particularly in environments where firmware updates or secure application loading is critical for system operation. The vulnerability affects devices that utilize Qualcomm's firmware management subsystem, including smartphones, tablets, and embedded systems that depend on UEFI secure application execution for proper system functionality.
Mitigation strategies for CVE-2024-46868 focus primarily on applying the upstream kernel fix that ensures proper lock release during error conditions. System administrators should prioritize updating to kernel versions that include the patched qcuefi_acquire() implementation, which correctly drops locks on error paths before returning. The fix aligns with established best practices for kernel concurrency management and follows the principle of releasing locks before returning from error handling routines. Organizations should also implement monitoring for unusual boot process delays or firmware loading timeouts that might indicate the vulnerability's exploitation. This vulnerability maps to CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization) and aligns with ATT&CK technique T1499.004 (Endpoint Denial of Service - Network Denial of Service) when considering the broader impact on system availability and boot integrity. The fix demonstrates proper resource management practices that are essential for maintaining kernel stability and preventing cascading failures in concurrent firmware loading scenarios.