Linux Kernel up to 7.2.4/7.3-rc1 bsg scsi_bsg_uring_cmd toctou

Summaryinfo

A vulnerability classified as very critical was found in Linux Kernel up to 7.2.4/7.3-rc1. The impacted element is the function scsi_bsg_uring_cmd of the component bsg. Executing a manipulation can lead to toctou. The identification of this vulnerability is CVE-2026-90009. The attack can only be executed locally. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 7.2.4/7.3-rc1. This vulnerability affects the function scsi_bsg_uring_cmd of the component bsg. The manipulation with an unknown input leads to a toctou vulnerability. The CWE definition for the vulnerability is CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: scsi: bsg: Fix TOCTOU in io_uring passthrough command setup scsi_bsg_uring_cmd() reads bsg_uring_cmd from the shared mmap'd SQE. Userspace can change a field after we check it and before we use it. request_len is the sharp case: it can grow past sizeof(scmd->cmnd) after the bound check and overflow scmd->cmnd in copy_from_user(). READ_ONCE() the SQE fields we check or use into locals before use.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-90009 since 09/11/2026. The exploitation appears to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/16/2026).

Upgrading to version 7.2.5 or 7.3-rc2 eliminates this vulnerability. Applying the patch f033530105aa73d82c121d54b57f358e4865d2f4/4b3c5965fca99f62d31c963294bd5b23cc488e97 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.3-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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