CVE-2023-52787 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
blk-mq: make sure active queue usage is held for bio_integrity_prep()
blk_integrity_unregister() can come if queue usage counter isn't held for one bio with integrity prepared, so this request may be completed with calling profile->complete_fn, then kernel panic.
Another constraint is that bio_integrity_prep() needs to be called before bio merge.
Fix the issue by:
- call bio_integrity_prep() with one queue usage counter grabbed reliably
- call bio_integrity_prep() before bio merge
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Analysis
by VulDB Data Team • 09/26/2025
The vulnerability identified as CVE-2023-52787 resides within the Linux kernel's block multi-queue subsystem, specifically affecting the blk-mq framework's handling of bio integrity operations. This flaw represents a critical race condition that can lead to system instability and potential kernel panic conditions. The issue manifests when the blk_integrity_unregister() function is invoked while a bio with integrity preparation is still active, creating a scenario where completion callbacks may be executed on already freed or improperly managed resources. The vulnerability is particularly concerning because it operates at the kernel level where improper resource management can result in complete system compromise rather than simple application failure.
The technical root cause of this vulnerability stems from improper synchronization and resource management within the block I/O subsystem. The flaw occurs when bio_integrity_prep() is called without ensuring that the queue usage counter remains valid throughout the operation lifecycle. This counter serves as a critical reference for maintaining proper resource ownership and prevents premature cleanup of active I/O operations. When the integrity preparation occurs without proper queue usage holding, it creates a window where the queue can be unregistered while still having active bio operations in progress, leading to execution of completion functions on invalid memory references. The vulnerability specifically impacts the ordering of operations where bio_integrity_prep() must be called before bio merge operations to maintain proper resource state.
The operational impact of CVE-2023-52787 extends beyond simple system crashes to encompass potential data integrity issues and service disruption in production environments. Systems utilizing block multi-queue configurations with integrity checking enabled are particularly vulnerable, including storage servers, database systems, and enterprise infrastructure relying on kernel-level I/O operations with data integrity verification. The race condition can be triggered through normal I/O workloads that involve integrity checking operations, making this vulnerability particularly dangerous as it can be exploited through legitimate system operations rather than requiring specialized attack vectors. When triggered, the vulnerability results in kernel panic conditions that require system reboot to recover, potentially leading to data loss or service interruption in mission-critical environments.
The fix implemented for CVE-2023-52787 addresses both the timing and synchronization issues by ensuring that bio_integrity_prep() operations are performed with proper queue usage counter management and by enforcing the correct ordering of operations. The solution requires that the queue usage counter be grabbed reliably before calling bio_integrity_prep(), preventing the scenario where the queue can be unregistered while active operations are still in progress. Additionally, the fix enforces that bio_integrity_prep() must be called before bio merge operations, ensuring proper resource state management throughout the I/O processing pipeline. This approach aligns with established security practices for kernel-level resource management and follows the principle of least privilege by ensuring proper resource ownership throughout the operation lifecycle. The mitigation strategy directly addresses the underlying CWE-362 vulnerability category related to race conditions and improper resource management in concurrent systems, providing a robust solution that prevents the kernel panic conditions while maintaining system stability and data integrity.
Organizations should prioritize patching systems running affected Linux kernel versions to prevent exploitation of this vulnerability. The fix requires kernel version updates that address the specific race condition in the blk-mq subsystem and ensure proper synchronization between integrity preparation and queue management operations. Security teams should monitor for systems that utilize block I/O operations with integrity checking enabled, as these represent the highest risk environment for exploitation. Regular kernel updates and proper system hardening practices should be maintained to prevent similar vulnerabilities from emerging in the storage subsystem. The vulnerability demonstrates the importance of proper kernel resource management and synchronization primitives in preventing critical system failures that can impact availability and data integrity across enterprise infrastructure.