Linux Kernel up to 6.18.32/7.0.9 net ena_com_phc_destroy active use after free

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.18.32/7.0.9. This affects the function ena_com_phc_destroy of the component net. The manipulation of the argument active results in use after free. This vulnerability is known as CVE-2026-52971. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.18.32/7.0.9. Affected is the function ena_com_phc_destroy of the component net. The manipulation of the argument active with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net: ena: PHC: Fix potential use-after-free in get_timestamp Move the phc->active check and resp pointer assignment to after acquiring the spinlock. Previously, phc->active was checked without holding the lock, and resp was cached from ena_dev->phc.virt_addr before the lock was acquired. If ena_com_phc_destroy() runs between the lockless active check and the lock acquisition, it sets active=false, releases the lock, frees the DMA memory, and sets virt_addr=NULL. The get_timestamp path would then read a NULL virt_addr and dereference it. With both the active check and the pointer read under the lock, destroy cannot free the memory while get_timestamp is using it.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-52971 since 06/09/2026. The exploitability is told to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/18/2026).

Upgrading to version 6.18.33 or 7.0.10 eliminates this vulnerability. Applying the patch 95e8ae9af2a61b4e72f5c585bf4c7d8aaf2a2c98/ca9ed40f28949353911dcb524ff8fff2f3409c97/e42c755582f0960e684298762f0ab927b3778376 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-2026-2077). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Oracle Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3
• 7.0.4
• 7.0.5
• 7.0.6
• 7.0.7
• 7.0.8
• 7.0.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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

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