CVE-2024-42223 in Linux
Summary
by MITRE • 07/30/2024
In the Linux kernel, the following vulnerability has been resolved:
media: dvb-frontends: tda10048: Fix integer overflow
state->xtal_hz can be up to 16M, so it can overflow a 32 bit integer when multiplied by pll_mfactor.
Create a new 64 bit variable to hold the calculations.
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Analysis
by VulDB Data Team • 07/19/2025
The vulnerability CVE-2024-42223 addresses a critical integer overflow issue within the Linux kernel's digital video broadcasting frontends subsystem, specifically affecting the tda10048 driver component. This flaw exists in the kernel's media handling infrastructure where the driver manages DVB (Digital Video Broadcasting) frontend devices, particularly those utilizing the tda10048 tuner chip. The vulnerability stems from insufficient integer width handling during frequency calculations, creating a potential pathway for arbitrary code execution or system instability when processing certain frequency parameters.
The technical flaw manifests when the driver processes the crystal frequency value stored in state->xtal_hz which can reach up to 16 megahertz. During normal operation, this value gets multiplied by pll_mfactor which represents a multiplier value for the phase-locked loop calculations. When these two values are combined in a 32-bit integer context, the multiplication operation can easily exceed the maximum representable value of a 32-bit signed integer, causing an integer overflow condition. This overflow corrupts the calculation results and can potentially lead to memory corruption or unexpected behavior in the kernel's memory management system.
The operational impact of this vulnerability extends beyond simple calculation errors as it represents a classic security weakness that could be exploited by malicious actors. The integer overflow creates a condition where attackers might manipulate the crystal frequency values to trigger the overflow, potentially leading to privilege escalation or denial of service conditions. This vulnerability affects systems running Linux kernels that include the affected DVB frontend driver code and could be particularly dangerous in embedded systems or devices where kernel-level stability is critical for proper operation. The flaw aligns with CWE-190, which specifically addresses integer overflow conditions, and represents a type of vulnerability that commonly appears in kernel drivers handling hardware-specific calculations.
Mitigation strategies for this vulnerability require immediate kernel updates from vendors who have released patches addressing the specific integer overflow issue. The fix implemented involves creating a new 64-bit variable to handle the intermediate calculations, ensuring that the multiplication of state->xtal_hz and pll_mfactor cannot overflow the integer bounds. This approach directly addresses the root cause by providing sufficient integer width to accommodate the maximum possible calculation results. System administrators should prioritize applying the kernel patches, particularly in environments where DVB frontend devices are actively used, as the vulnerability could be exploited to gain unauthorized access to system resources or disrupt normal device operation. Additionally, monitoring for unusual frequency calculations or system behavior patterns can help detect potential exploitation attempts, though the primary defense remains the patched kernel implementation.