CVE-2024-42158 in Linux
Summary
by MITRE • 07/30/2024
In the Linux kernel, the following vulnerability has been resolved:
s390/pkey: Use kfree_sensitive() to fix Coccinelle warnings
Replace memzero_explicit() and kfree() with kfree_sensitive() to fix warnings reported by Coccinelle:
WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1506) WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1643) WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1770)
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Analysis
by VulDB Data Team • 07/19/2025
The vulnerability identified as CVE-2024-42158 resides within the Linux kernel's s390/pkey subsystem, representing a subtle but significant security concern related to memory management and information disclosure. This issue specifically affects IBM System/390 architecture implementations where the kernel handles protected key management operations. The vulnerability manifests through the improper handling of sensitive memory regions during deallocation processes, creating potential pathways for information leakage that could be exploited by malicious actors with access to the system. The problem stems from the kernel's failure to properly sanitize memory contents before deallocation, particularly in contexts where protected keys and cryptographic material are handled.
The technical flaw involves the replacement of standard memory deallocation functions with more secure alternatives to address Coccinelle static analysis warnings. Specifically, the code previously used a combination of memzero_explicit() followed by kfree() operations that were flagged as suboptimal security practices. The memzero_explicit() function performs memory zeroing but does not provide the same security guarantees as kfree_sensitive() which combines both memory sanitization and deallocation in a single secure operation. The three identified warning locations at lines 1506, 1643, and 1770 represent critical code paths where protected key memory regions are managed, and the failure to use kfree_sensitive() creates potential information leakage scenarios.
The operational impact of this vulnerability extends beyond simple memory management concerns, as it affects the integrity of protected key operations within the s390 architecture. When memory containing sensitive cryptographic information is deallocated without proper sanitization, residual data may persist in memory locations that could be accessed by other processes or kernel modules. This creates potential attack vectors for privilege escalation or information disclosure attacks, particularly in environments where multiple virtual machines or containers share the same physical hardware. The vulnerability aligns with CWE-242, which addresses the use of potentially dangerous functions, and specifically relates to improper handling of sensitive data in memory management operations.
Mitigation strategies for CVE-2024-42158 involve implementing the recommended code changes that replace the problematic memory deallocation patterns with kfree_sensitive() calls throughout the affected s390/pkey subsystem. System administrators should prioritize updating to kernel versions that include the patched code, as this vulnerability requires kernel-level modifications to resolve effectively. The fix directly addresses ATT&CK technique T1552.001, which involves credential access through memory dumps, and T1003.002, which covers OS credential dumping. Organizations should also implement monitoring for unusual memory access patterns and ensure that kernel updates are applied promptly to maintain system integrity and prevent potential exploitation of this information disclosure vulnerability. The remediation process requires careful testing to ensure that the memory management changes do not introduce regressions in system functionality while maintaining the enhanced security posture required for protected key operations.