CVE-2026-64485 in Linux
Summary
by MITRE • 07/25/2026
In the Linux kernel, the following vulnerability has been resolved:
ALSA: compress: Fix task creation error unwind
snd_compr_task_new() allocates the driver task before validating the returned DMA buffers and reserving file descriptors. When either of those later steps fails, the core frees its task wrapper and DMA-buffer references without calling the driver's task_free() callback. Any driver resources allocated by task_create() are therefore leaked.
The dual-fd allocation path also jumps to cleanup without storing the negative get_unused_fd_flags() result in retval. Since retval still contains the successful task_create() return value, TASK_CREATE can incorrectly report success although the task was discarded.
Preserve the fd allocation errors and call task_free() when failure occurs after a successful task_create() callback.
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Analysis
by VulDB Data Team • 07/25/2026
This vulnerability resides within the Advanced Linux Sound Architecture subsystem of the Linux kernel, specifically affecting the compressed audio data path implementation. The issue manifests in the snd_compr_task_new() function which orchestrates the creation of driver tasks for compressed audio processing. The flaw represents a classic resource management error where the kernel fails to properly unwind allocated resources when subsequent validation steps encounter failures during task creation. This creates a scenario where driver-specific resources remain allocated indefinitely, leading to potential memory leaks and system instability.
The technical implementation details reveal a problematic execution flow where the function performs allocation operations in an incorrect order relative to validation checks. The kernel allocates driver tasks before validating essential DMA buffer availability and file descriptor reservation status. When either of these later validation steps fails, the core subsystem correctly frees its own task wrapper and DMA-buffer references but neglects to invoke the driver's dedicated task_free() callback mechanism. This oversight creates a resource leak scenario as any driver-specific allocations made during the successful task_create() callback remain unreleased, potentially leading to gradual system resource exhaustion over time.
The operational impact of this vulnerability extends beyond simple memory leaks to encompass potential system stability issues and denial of service conditions. Attackers could theoretically exploit this weakness by repeatedly triggering compressed audio task creation failures, causing progressive accumulation of leaked driver resources that could eventually degrade system performance or trigger kernel panic conditions. The dual-fd allocation path presents an additional complexity where error handling logic fails to properly capture negative return values from get_unused_fd_flags() calls, creating a scenario where failure conditions are incorrectly reported as success states. This misreporting can mask underlying resource allocation problems and complicate debugging efforts.
The vulnerability aligns with CWE-459 which describes incomplete cleanup issues in software systems, specifically representing a resource leak scenario where allocated resources are not properly released during error conditions. From an ATT&CK framework perspective, this represents a potential privilege escalation vector through resource exhaustion attacks or system stability degradation that could be leveraged by malicious actors to compromise system integrity. The fix requires reordering the validation sequence to ensure proper error handling flow and implementing correct return value management for file descriptor allocations, ensuring that task_free() callbacks are invoked consistently regardless of whether subsequent validation steps succeed or fail.
Mitigation strategies should focus on immediate kernel updates to address the specific resource management flaw in the ALSA subsystem. System administrators should prioritize patching affected kernel versions, particularly those running compressed audio processing workloads where this vulnerability could be exploited. Monitoring for unusual memory consumption patterns or audio subsystem instability may help detect exploitation attempts. Additionally, implementing proper error handling procedures and ensuring comprehensive testing of resource allocation sequences can prevent similar issues in future implementations. The fix demonstrates the critical importance of maintaining consistent resource management practices throughout complex kernel subsystems where multiple allocation operations must be coordinated properly to avoid partial state inconsistencies that could lead to security vulnerabilities.