Linux Kernel up to 7.2.6/7.3-rc1 BPF bpf_sys_bpf/bpf_sys_close allocation of resources

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.2.6/7.3-rc1. It has been rated as problematic. The affected element is the function bpf_sys_bpf/bpf_sys_close of the component BPF. The manipulation leads to allocation of resources. This vulnerability is uniquely identified as CVE-2026-98058. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.6/7.3-rc1 and classified as problematic. This issue affects the function bpf_sys_bpf/bpf_sys_close of the component BPF. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: bpf: Mark syscall helpers as sleepable bpf_sys_bpf() executes the bpf(2) syscall body, which can take mutexes, allocate with GFP_KERNEL, and wait for an RCU grace period. bpf_sys_close() reaches close_fd() and filp_close(), which can sleep as well. Both helpers are limited to BPF_PROG_TYPE_SYSCALL, whose main program is sleepable. That does not make every callback sleepable: a syscall program can register a bpf_timer callback, and the verifier checks that callback in a non-sleepable context while retaining the syscall helper set. Without .might_sleep on the prototypes, such a callback can invoke bpf_sys_bpf() from hrtimer softirq context and trigger a scheduling-while-atomic failure. bpf_sys_close() is exposed through the same missing context check. Set .might_sleep on both prototypes so the existing helper-context check rejects them from timer callbacks and other atomic regions. Calls from the sleepable main body remain valid.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-98058 since 09/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are required for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 7.2.7 or 7.3-rc2 eliminates this vulnerability. Applying the patch 3408e98f06ce06ea6a58ca6c39da9c23f0029c06/d05524794240b52fdc3b6c1220dd05505715824d 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
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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