Vulnerability in Kernel package: scsi: lpfc: Fix null pointer dereference in lpfc_prep_els_iocb()
Summary
UVI-2021-1000276: scsi: lpfc: Fix null pointer dereference in lpfc_prep_els_iocb(). Affects Kernel versions >= 4430f7fd09ecb037570119e0aacbf0c17b8f98b2, < 9bdcfbed2a9fe24d2c7eaa1bad7c705e18de8cc7. No fix is published. How to fix ↓
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Background
The Kernel package is a crucial component of the Linux operating system, responsible for managing the system's core functionality. It provides an interface between the hardware and software layers, allowing applications to communicate with the underlying hardware. The scsi subsystem within the Kernel package handles SCSI (Small Computer System Interface) devices, enabling data transfer between the computer and storage devices. One of the components in the scsi subsystem is the lpfc driver, which is used for Fibre Channel over Ethernet (FCoE) communication. The lpfc_prep_els_iocb() function within the lpfc driver is responsible for preparing an ELS (Exchange Link Service) IOCB (I/O Control Block) for transmission. However, a vulnerability has been identified in this function, leading to a null pointer dereference.
Vulnerability Detail
The null pointer dereference vulnerability in the lpfc_prep_els_iocb() function of the lpfc driver can be exploited by an attacker to cause a denial-of-service (DoS) condition or potentially execute arbitrary code with kernel privileges. By sending a specially crafted request to the vulnerable system, an attacker can trigger the null pointer dereference, resulting in a system crash or potential code execution. This vulnerability was introduced in version v5.11 of the Linux Kernel and was fixed in version v5.12.4.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a temporary workaround, users can disable the lpfc driver if it is not required for their system. This can be achieved by blacklisting the lpfc module. To blacklist the lpfc module, add the following line to the '/etc/modprobe.d/blacklist.conf' file:
blacklist lpfc
After adding the blacklist entry, reboot the system for the changes to take effect. However, it is important to note that this workaround may impact the functionality of Fibre Channel over Ethernet (FCoE) communication if the lpfc driver is needed.
Conclusion
The vulnerability in the Kernel package's scsi subsystem, specifically the lpfc_prep_els_iocb() function, could allow an attacker to cause a denial-of-service (DoS) condition or potentially execute arbitrary code with kernel privileges. It is crucial to update the Linux Kernel package to version v5.12.4 or later to mitigate this vulnerability. Additionally, users can apply a temporary workaround by disabling the lpfc driver if it is not required. For further support and assistance in vulnerability remediation, please contact DevNack.com.
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FAQ
This vulnerability can lead to a denial-of-service (DoS) condition or potential code execution with kernel privileges. An attacker can exploit the vulnerability to crash the system or execute arbitrary code.
You can use the Vulert Playground at Vulert Scanner to check if your system is affected by this vulnerability. The Vulert Playground allows you to analyze your application's manifest file, such as package-lock.json, and provides real-time alerts for open-source vulnerabilities.
Yes, a temporary workaround is to disable the lpfc driver by blacklisting the lpfc module. However, this may impact the functionality of Fibre Channel over Ethernet (FCoE) communication if the lpfc driver is required.
To update the Linux Kernel package, you can obtain the latest version from the official Linux Kernel repository. It is recommended to update to version v5.12.4 or later, which includes the necessary patch to fix the vulnerability.
Yes, after updating the Kernel package, it is recommended to reboot the system for the changes to take effect.
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