CVE-2024-47756 in Linux
Summary
by MITRE • 10/21/2024
In the Linux kernel, the following vulnerability has been resolved:
PCI: keystone: Fix if-statement expression in ks_pcie_quirk()
This code accidentally uses && where || was intended. It potentially results in a NULL dereference.
Thus, fix the if-statement expression to use the correct condition.
[kwilczynski: commit log]
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Analysis
by VulDB Data Team • 01/19/2026
The vulnerability identified as CVE-2024-47756 resides within the Linux kernel's PCI subsystem, specifically affecting the Keystone PCIe driver implementation. This flaw manifests in the ks_pcie_quirk() function where a logical operator error creates a critical condition that could lead to system instability. The vulnerability represents a classic programming error where the && operator was mistakenly employed instead of the || operator in a conditional statement, creating an unexpected execution path that undermines the driver's robustness. This particular issue falls under the category of improper control flow handling, which is categorized as CWE-483 in the Common Weakness Enumeration framework, highlighting the fundamental flaw in the programmer's intent regarding conditional logic evaluation.
The technical implementation of this vulnerability occurs within the Keystone PCIe driver module responsible for handling specific quirks and workarounds for PCIe devices on Keystone hardware platforms. When the ks_pcie_quirk() function executes, the incorrect logical operator causes the conditional check to fail in its intended validation, potentially allowing execution to proceed down a code path that assumes certain pointer values are non-null. This misconfiguration creates a scenario where a NULL pointer dereference can occur, leading to kernel panic or system crash when the driver attempts to access memory through an invalid pointer reference. The flaw demonstrates a lack of proper null pointer validation and conditional logic construction that is fundamental to secure kernel programming practices.
The operational impact of this vulnerability extends beyond simple system instability to potentially compromise the entire system integrity when the Keystone PCIe driver is active. System administrators and embedded device operators using Keystone-based platforms may experience unexpected system crashes or reboots when PCIe devices are enumerated or accessed through the affected driver. The vulnerability is particularly concerning in embedded systems and server environments where PCIe device functionality is critical for network connectivity, storage operations, or other essential hardware functions. This issue directly relates to the ATT&CK technique T1490 which involves exploitation of system resource exhaustion or manipulation, as the NULL dereference could potentially be leveraged to cause system instability or denial of service conditions that disrupt normal operations.
Mitigation strategies for CVE-2024-47756 focus primarily on applying the official kernel patch that corrects the logical operator error in the ks_pcie_quirk() function. System administrators should prioritize updating their kernel installations to versions that include this fix, particularly those running on Keystone-based hardware platforms where the PCIe driver is actively utilized. The patch implementation requires careful verification through kernel version checking and testing procedures to ensure that the fix does not introduce compatibility issues with existing hardware configurations. Additionally, organizations should implement monitoring systems to detect potential system crashes or unexpected reboots that might indicate exploitation attempts, while maintaining regular kernel update schedules to address similar vulnerabilities proactively. The fix itself represents a straightforward correction that aligns with secure coding practices and demonstrates the importance of thorough code review processes in kernel development environments where such low-level errors can have significant system-wide consequences.