CVE-2026-22994
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2026-01-23

Last updated on: 2026-02-26

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix reference count leak in bpf_prog_test_run_xdp() syzbot is reporting unregister_netdevice: waiting for sit0 to become free. Usage count = 2 problem. A debug printk() patch found that a refcount is obtained at xdp_convert_md_to_buff() from bpf_prog_test_run_xdp(). According to commit ec94670fcb3b ("bpf: Support specifying ingress via xdp_md context in BPF_PROG_TEST_RUN"), the refcount obtained by xdp_convert_md_to_buff() will be released by xdp_convert_buff_to_md(). Therefore, we can consider that the error handling path introduced by commit 1c1949982524 ("bpf: introduce frags support to bpf_prog_test_run_xdp()") forgot to call xdp_convert_buff_to_md().
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Meta Information
Published
2026-01-23
Last Modified
2026-02-26
Generated
2026-05-07
AI Q&A
2026-01-23
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 9 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel From 5.18 (inc) to 6.1.161 (exc)
linux linux_kernel From 6.13 (inc) to 6.18.6 (exc)
linux linux_kernel From 6.2 (inc) to 6.6.121 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.66 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a reference count leak in the Linux kernel's BPF subsystem, specifically in the function bpf_prog_test_run_xdp(). The issue arises because an error handling path introduced in a recent commit forgot to call a function (xdp_convert_buff_to_md()) that releases a reference count obtained earlier by xdp_convert_md_to_buff(). This leads to a situation where the usage count of a network device (sit0) does not decrease properly, causing the device to remain in use longer than it should.


How can this vulnerability impact me? :

The impact of this vulnerability is that it can cause resource leaks in the Linux kernel, specifically leaking reference counts on network devices. This can lead to network devices not being freed properly, potentially causing system instability, resource exhaustion, or preventing network interfaces from being released or reused as expected.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by monitoring for the specific error message 'unregister_netdevice: waiting for sit0 to become free. Usage count = 2' in the system logs, which indicates a reference count leak related to bpf_prog_test_run_xdp(). You can use commands like 'dmesg | grep unregister_netdevice' or 'journalctl -k | grep unregister_netdevice' to check for this message.


What immediate steps should I take to mitigate this vulnerability?

Immediate mitigation involves updating the Linux kernel to a version that includes the fix for the reference count leak in bpf_prog_test_run_xdp(), as the issue is resolved by correcting the error handling path to properly release the reference count.


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