Linux Kernel up to 7.1.4 bpf __clean_func_state stack-based overflow

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.1.4 and classified as very critical. This vulnerability affects the function __clean_func_state of the component bpf. The manipulation results in stack-based overflow. This vulnerability is cataloged as CVE-2026-72426. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.1.4. Affected is the function __clean_func_state of the component bpf. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bpf: Preserve pointer spill metadata during half-slot cleanup __clean_func_state() cleans dead stack slots in 4-byte halves. When the high half of a STACK_SPILL slot is dead and the low half remains live, cleanup converts the live low half to STACK_MISC or STACK_ZERO and clears the saved spilled_ptr metadata. That conversion is safe only for scalar spills. For a pointer spill, this metadata clear lets a later 32-bit fill from the still-live half avoid the normal non-scalar register-fill check and be treated as an ordinary scalar stack read. Leave non-scalar spill slots intact in this half-live shape. This is conservative for pruning and preserves the existing check_stack_read_fixed_off() rejection path for partial fills from pointer spills.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-72426 since 08/09/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. 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 08/15/2026).

Upgrading to version 7.1.5 or 7.2-rc1 eliminates this vulnerability. Applying the patch 0f9278b22cda6fd2525049930157b79b4036b4ef/3a354149bceacadbcf7d7b4766f5ef26a85892ab is able to eliminate this problem.

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

• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

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