Linux Kernel up to 7.1.8 pca953x pca953x_irq_bus_sync_unlock locking

Summaryinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.1.8. Affected by this issue is the function pca953x_irq_bus_sync_unlock of the component pca953x. The manipulation leads to locking. This vulnerability is referenced as CVE-2026-74733. The attack can only be performed from a local environment. No exploit is available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.1.8. It has been rated as very critical. This issue affects the function pca953x_irq_bus_sync_unlock of the component pca953x. The manipulation with an unknown input leads to a locking vulnerability. Using CWE to declare the problem leads to CWE-667. The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock Locking is disabled in the regmap config as this driver uses its own lock. This means that all calls to regmap functions (read or write) must hold the i2c_lock. The function pca953x_irq_bus_sync_unlock() did not do this, and it was therefore possible that multiple threads could cause an incorrect register to be read/written. A previous patch partly fixed this, but only protected the write to the interrupt mask register, and not the read from the direction register.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-74733 since 08/15/2026. The exploitation is known to be easy. An attack has to be approached locally. The exploitation requires an enhanced level of successful authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/22/2026).

Upgrading to version 7.1.9 eliminates this vulnerability. Applying the patch e6a2f5f845f50b0c4299bace5111f56d3390a090/9dc325327babe7f159e84cbe9380a45342da0585 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-64420). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7
• 7.1.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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