Linux Kernel up to 6.19.13 srcu_gp_start_if_needed use after free

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.19.13. It has been declared as critical. The impacted element is the function srcu_gp_start_if_needed. Such manipulation leads to use after free. This vulnerability is documented as CVE-2026-43115. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.19.13 and classified as critical. Affected by this issue is the function srcu_gp_start_if_needed. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: srcu: Use irq_work to start GP in tiny SRCU Tiny SRCU's srcu_gp_start_if_needed() directly calls schedule_work(), which acquires the workqueue pool->lock. This causes a lockdep splat when call_srcu() is called with a scheduler lock held, due to: call_srcu() [holding pi_lock] srcu_gp_start_if_needed() schedule_work() -> pool->lock workqueue_init() / create_worker() [holding pool->lock] wake_up_process() -> try_to_wake_up() -> pi_lock Also add irq_work_sync() to cleanup_srcu_struct() to prevent a use-after-free if a queued irq_work fires after cleanup begins. Tested with rcutorture SRCU-T and no lockdep warnings. [ Thanks to Boqun for similar fix in patch "rcu: Use an intermediate irq_work to start process_srcu()" ]

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-43115 since 05/01/2026. The exploitation is known to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 06/09/2026).

Upgrading to version 6.19.14 eliminates this vulnerability. Applying the patch bb37286db65368cb72ba8757ad86299c4e4a73fc/a6fc88b22bc8d12ad52e8412c667ec0f5bf055af 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 CERT Bund (WID-SEC-2026-1385). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Microsoft Azure Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8
• 6.19.9
• 6.19.10
• 6.19.11
• 6.19.12
• 6.19.13

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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

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