Linux Kernel up to 5.14.11 iscsi_get_conn/iscsi_put_conn use after free

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.14.11. It has been declared as problematic. This affects the function iscsi_get_conn/iscsi_put_conn. Executing a manipulation can lead to use after free. This vulnerability is tracked as CVE-2021-47427. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 5.14.11 and classified as problematic. This vulnerability affects the function iscsi_get_conn/iscsi_put_conn. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: scsi: iscsi: Fix iscsi_task use after free Commit d39df158518c ("scsi: iscsi: Have abort handler get ref to conn") added iscsi_get_conn()/iscsi_put_conn() calls during abort handling but then also changed the handling of the case where we detect an already completed task where we now end up doing a goto to the common put/cleanup code. This results in a iscsi_task use after free, because the common cleanup code will do a put on the iscsi_task. This reverts the goto and moves the iscsi_get_conn() to after we've checked if the iscsi_task is valid.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2021-47427. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 12/31/2024).

The vulnerability scanner Nessus provides a plugin with the ID 209785 (EulerOS Virtualization 2.12.0 : kernel (EulerOS-SA-2024-2781)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.14.12 eliminates this vulnerability. Applying the patch 1642f51ac0d4/258aad75c621 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (209785). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.14.0
• 5.14.1
• 5.14.2
• 5.14.3
• 5.14.4
• 5.14.5
• 5.14.6
• 5.14.7
• 5.14.8
• 5.14.9
• 5.14.10
• 5.14.11

License

• open-source

Website

• Vendor: https://www.kernel.org/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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