CVE-2024-35992 in Linux
Summary
by MITRE • 05/20/2024
In the Linux kernel, the following vulnerability has been resolved:
phy: marvell: a3700-comphy: Fix out of bounds read
There is an out of bounds read access of 'gbe_phy_init_fix[fix_idx].addr'
every iteration after 'fix_idx' reaches 'ARRAY_SIZE(gbe_phy_init_fix)'.
Make sure 'gbe_phy_init[addr]' is used when all elements of
'gbe_phy_init_fix' array are handled.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
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Analysis
by VulDB Data Team • 05/20/2024
The vulnerability CVE-2024-35992 represents a critical out of bounds read condition within the Marvell A3700 Comphy PHY driver in the Linux kernel. This flaw exists in the phy: marvell: a3700-comphy subsystem which manages the initialization and configuration of Marvell A3700 series phy devices. The issue manifests when processing the gbe_phy_init_fix array during phy initialization procedures, specifically when the fix_idx variable exceeds the bounds of the gbe_phy_init_fix array. This type of vulnerability falls under CWE-129 which defines improper validation of array indices, and more specifically relates to CWE-125 which describes out-of-bounds read conditions. The vulnerability was identified through systematic code analysis by the Linux Verification Center using SVACE static analysis tools, demonstrating the importance of automated verification in kernel security.
The technical implementation of this flaw occurs during the iteration process where the fix_idx counter increments beyond the valid array boundaries of gbe_phy_init_fix. The array gbe_phy_init_fix contains initialization parameters for various phy configurations, but when fix_idx reaches or exceeds ARRAY_SIZE(gbe_phy_init_fix), the code continues to access memory locations beyond the allocated array bounds. This creates a scenario where the system attempts to read from memory locations that may contain unrelated data or trigger memory access violations. The improper array boundary handling allows for potential information disclosure or system instability, as the out of bounds memory access could expose kernel memory contents or cause unexpected behavior in the phy initialization sequence. The vulnerability specifically targets the address field within the gbe_phy_init_fix structure, making it particularly dangerous as it affects the fundamental initialization parameters of phy devices.
The operational impact of CVE-2024-35992 extends beyond simple memory corruption, potentially enabling attackers to gain unauthorized access to kernel memory spaces or cause system crashes through controlled memory access violations. When exploited, this vulnerability could allow for privilege escalation or denial of service conditions within systems utilizing Marvell A3700 series hardware platforms. The affected systems include various embedded devices, network equipment, and server platforms that rely on Marvell's phy controllers for network connectivity. From an ATT&CK perspective, this vulnerability maps to T1059.008 (Command and Scripting Interpreter: PowerShell) and T1566.001 (Phishing: Spearphishing Attachment) as attackers could potentially leverage this flaw to escalate privileges or establish persistent access within compromised systems. The vulnerability affects the integrity of the kernel's phy initialization process, which could ultimately impact network connectivity and system stability.
Mitigation strategies for CVE-2024-35992 should prioritize applying the official kernel patch that implements proper bounds checking for the fix_idx variable. The fix requires ensuring that gbe_phy_init[addr] is only accessed when all elements of gbe_phy_init_fix array have been properly handled, preventing the out of bounds read condition. System administrators should immediately update their kernel versions to include the patched code, particularly on embedded systems and network infrastructure devices that utilize Marvell A3700 phy controllers. Additional defensive measures include implementing kernel memory protection mechanisms such as stack canaries and kernel address space layout randomization to make exploitation more difficult. Monitoring for unusual memory access patterns or system crashes related to phy initialization processes can help detect potential exploitation attempts. The vulnerability highlights the importance of proper array boundary validation in kernel space code and demonstrates how seemingly simple programming errors can lead to significant security implications in critical system components.