Linux Kernel up to 7.2.3 Tracing simple_ring_buffer_swap_reader_page behavioral workflow

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.2.3. It has been rated as very critical. This affects the function simple_ring_buffer_swap_reader_page of the component Tracing. Performing a manipulation results in behavioral workflow. This vulnerability is identified as CVE-2026-89748. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.2.3. This affects the function simple_ring_buffer_swap_reader_page of the component Tracing. The manipulation with an unknown input leads to a behavioral workflow vulnerability. CWE is classifying the issue as CWE-841. The product supports a session in which more than one behavior must be performed by an actor, but it does not properly ensure that the actor performs the behaviors in the required sequence. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. The current !retry test reverses both outcomes. It returns an error after a successful final replacement, leaving the link update complete but the reader bookkeeping unfinished. After a failed final replacement, it falls through and updates the head and reader pointers as though the replacement succeeded, which can corrupt the ring. Treat only a negative counter as exhaustion and return the documented -EBUSY error.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-89748 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/11/2026).

Upgrading to version 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch df02489aa3aa1834659f0d20c89f7d212047d268/e0d3aed7b12cf37b74c7cc5265073d0263b49cde is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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