Vulnerability in Kernel: Put LLD module refcnt after SCSI device is released
Summary
GSD-2021-1002144: scsi: core: Put LLD module refcnt after SCSI device is released. Affects Kernel versions < f30822c0b4c35ec86187ab055263943dc71a6836. No fix is published. How to fix ↓
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Background
The Kernel is a crucial component of the Linux operating system that provides core functionality and interfaces with hardware devices. It manages the communication between software and hardware, including the SCSI (Small Computer System Interface) devices. SCSI is a standard for connecting and transferring data between computers and peripheral devices, such as hard drives and tape drives. The vulnerability in the Kernel arises from a flaw in the handling of LLD (Low-Level Driver) module reference counts after a SCSI device is released.
Vulnerability Detail
The vulnerability occurs in the SCSI core of the Kernel. When a SCSI device is released, the LLD module reference count is not properly decremented, leading to a use-after-free vulnerability. An attacker could potentially exploit this vulnerability to execute arbitrary code or cause a denial-of-service condition. The impact and attack plausibility of this vulnerability have not been proven yet. It is important to note that this vulnerability has been fixed in Linux Kernel version v5.14.17 by commit f30822c0b4c35ec86187ab055263943dc71a6836.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
If updating the Kernel is not immediately feasible, a possible workaround is to disable or remove the affected LLD module from the system. However, this workaround may impact the functionality of SCSI devices that rely on the module. It is recommended to consult the documentation or support channels for the specific LLD module to determine the appropriate course of action.
Conclusion
The vulnerability in the Kernel's SCSI core, which involves the improper handling of LLD module reference counts after releasing a SCSI device, could potentially lead to arbitrary code execution or denial-of-service. It is crucial to update the Linux Kernel to version v5.14.17 or later to mitigate this vulnerability. If immediate updating is not possible, consider disabling or removing the affected LLD module, but be aware of potential impacts on SCSI device functionality. For further support on vulnerability remediation, please contact DevNack.com.
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FAQ
The Kernel is a core component of the Linux operating system that provides essential functionality and interfaces with hardware devices.
SCSI (Small Computer System Interface) is a standard for connecting and transferring data between computers and peripheral devices, such as hard drives and tape drives.
An LLD (Low-Level Driver) module is a component that provides the necessary software interface for a specific hardware device, such as a SCSI device.
A use-after-free vulnerability occurs when a program continues to use a memory reference after it has been freed, potentially leading to unexpected behavior or security issues.
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