CVE-2024-38579 in Linux
Summary
by MITRE • 06/19/2024
In the Linux kernel, the following vulnerability has been resolved:
crypto: bcm - Fix pointer arithmetic
In spu2_dump_omd() value of ptr is increased by ciph_key_len instead of hash_iv_len which could lead to going beyond the buffer boundaries. Fix this bug by changing ciph_key_len to hash_iv_len.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
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Analysis
by VulDB Data Team • 10/21/2025
The vulnerability identified as CVE-2024-38579 resides within the Linux kernel's cryptographic subsystem, specifically in the bcm (Broadcom) crypto driver implementation. This flaw manifests in the spu2_dump_omd() function where improper pointer arithmetic leads to potential buffer overflow conditions. The cryptographic framework within Linux kernels plays a critical role in securing system operations through encryption and hashing functions, making such vulnerabilities particularly concerning for system integrity and security posture. The issue was discovered through systematic analysis by the Linux Verification Center, which employs advanced static analysis tools to identify potential security flaws in kernel code.
The technical flaw involves incorrect pointer arithmetic within the cryptographic processing function where the pointer variable ptr is incremented by ciph_key_len instead of the intended hash_iv_len value. This seemingly minor code error has significant implications as it causes the pointer to traverse beyond the allocated buffer boundaries, potentially accessing memory locations outside the intended scope. The vulnerability stems from a fundamental misunderstanding in the arithmetic operation that governs how the pointer advances through memory during cryptographic operations. According to CWE classification, this represents a CWE-129: Improper Validation of Array Index, which occurs when an application does not validate that array indices are within the valid range before accessing array elements. The improper pointer arithmetic creates an exploitable condition that could allow attackers to manipulate memory contents or potentially execute arbitrary code.
The operational impact of this vulnerability extends beyond simple memory corruption as it affects the core cryptographic operations within the Linux kernel. When the pointer arithmetic error occurs, it may lead to data corruption within the cryptographic buffers, potentially compromising the integrity of encrypted data or authentication tokens. The vulnerability affects systems utilizing Broadcom crypto hardware accelerators where the spu2_dump_omd() function is invoked during cryptographic processing. Attackers could potentially exploit this condition to gain unauthorized access to cryptographic keys or manipulate encrypted data flows, undermining the security guarantees that cryptographic operations are designed to provide. The vulnerability aligns with ATT&CK technique T1552.004: File and Directory Permissions Modification, as it could enable privilege escalation or data manipulation through cryptographic function manipulation.
The fix implemented for CVE-2024-38579 involves a straightforward but critical code correction where ciph_key_len is replaced with hash_iv_len in the pointer arithmetic operation. This change ensures that the pointer advances by the correct buffer size corresponding to the hash initialization vector length rather than the cipher key length. The correction addresses the root cause by aligning the pointer arithmetic with the actual buffer dimensions and processing requirements. This type of vulnerability demonstrates the importance of careful code review and static analysis in kernel development, as even minor arithmetic errors can have significant security implications. The resolution represents a standard defensive programming practice where buffer boundaries are properly validated before pointer operations. The vulnerability was identified through automated static analysis tools, highlighting the necessity of comprehensive testing methodologies in kernel security assurance. The fix ensures that cryptographic operations maintain proper memory boundaries and prevents potential exploitation through buffer overflow conditions that could compromise system security.