CVE-2026-23252 in Linux
Summary
by MITRE • 03/18/2026
In the Linux kernel, the following vulnerability has been resolved:
xfs: get rid of the xchk_xfile_*_descr calls
The xchk_xfile_*_descr macros call kasprintf, which can fail to allocate memory if the formatted string is larger than 16 bytes (or whatever the nofail guarantees are nowadays). Some of them could easily exceed that, and Jiaming Zhang found a few places where that can happen with syzbot.
The descriptions are debugging aids and aren't required to be unique, so let's just pass in static strings and eliminate this path to failure. Note this patch touches a number of commits, most of which were merged between 6.6 and 6.14.
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Analysis
by VulDB Data Team • 06/02/2026
The vulnerability identified as CVE-2026-23252 resides within the Linux kernel's XFS filesystem implementation, specifically addressing a memory allocation failure scenario that could lead to system instability. This issue manifests through the xchk_xfile_*_descr macros which utilize kasprintf for dynamic string formatting during filesystem checking operations. The root cause stems from the fact that kasprintf can fail when attempting to allocate memory for formatted strings that exceed predetermined size limits, typically around 16 bytes in current kernel implementations. The vulnerability was discovered through automated testing by syzbot, which identified scenarios where these macros could be invoked with string formats that easily surpass the memory allocation boundaries, creating potential denial of service conditions or system crashes.
The technical flaw represents a classic memory management issue within kernel space operations, where debugging aids intended to provide descriptive information become a point of system failure. The xchk_xfile_*_descr macros are designed to generate descriptive strings for filesystem checking operations, but their reliance on dynamic memory allocation through kasprintf creates a path where allocation failures can propagate through the system. This particular vulnerability demonstrates poor resource management practices in kernel code where debugging functionality inadvertently creates attack surfaces or reliability issues. The issue is particularly concerning because it affects the filesystem checking infrastructure which is critical for maintaining data integrity and system stability. According to CWE-704, this represents a weakness in resource management where insufficient error handling for memory allocation failures can lead to system instability. The vulnerability operates under the principle that kernel debugging aids should not compromise system reliability, yet the current implementation fails to account for memory allocation constraints in dynamic string generation.
The operational impact of this vulnerability extends beyond simple memory allocation failures to potentially compromise entire filesystem checking operations and system stability. When the kasprintf calls fail due to memory constraints, the filesystem checking process may terminate prematurely or behave unpredictably, leading to potential data corruption scenarios or complete system lockups. The vulnerability affects systems running kernel versions between 6.6 and 6.14 where the affected commits were merged, making it a widespread issue across multiple kernel releases. The implications are particularly severe in production environments where filesystem integrity checking is critical for maintaining data reliability. From an ATT&CK perspective, this vulnerability could be leveraged in a denial of service attack scenario where an attacker could potentially trigger memory allocation failures through specific filesystem operations, though the attack surface is limited to kernel-level operations. The patch addresses this by replacing dynamic string generation with static strings, eliminating the memory allocation dependency while preserving the debugging functionality's core purpose.
The mitigation strategy implemented in the patch focuses on eliminating the problematic kasprintf calls by replacing them with static string references, which removes the memory allocation dependency entirely. This approach aligns with kernel security best practices that emphasize avoiding dynamic memory allocation in critical code paths where reliability is paramount. The fix ensures that debugging information remains available while eliminating the potential for memory allocation failures that could compromise system stability. The patch touches multiple commits across the kernel version range, indicating a coordinated effort to address this issue throughout the kernel's development cycle. This resolution demonstrates the importance of considering resource constraints in kernel development, particularly for debugging and diagnostic code that should never become a point of system failure. The change maintains backward compatibility while significantly reducing the attack surface and reliability risks associated with the filesystem checking infrastructure. Security practitioners should monitor kernel updates to ensure systems are patched against this vulnerability, particularly in environments where filesystem integrity checking is frequently performed or where system stability is critical. The fix also serves as a reminder to kernel developers about the importance of robust error handling in all code paths, even those considered debugging aids, as these can become critical system components under certain conditions.