CVE-2025-21836

io_uring/kbuf: reallocate buf lists on upgrade

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: reallocate buf lists on upgrade IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it was created for legacy selected buffer and has been emptied. It violates the requirement that most of the field should stay stable after publish. Always reallocate it instead.

N/A

CVSS

Severity:

EPSS 0.03%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/146a185f6c05ee263db715f860620606303c4633
https://git.kernel.org/stable/c/7d0dc28dae836caf7645fef62a10befc624dd17b
https://git.kernel.org/stable/c/2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4
https://git.kernel.org/stable/c/8802766324e1f5d414a81ac43365c20142e85603

Frequently Asked Questions

What is the severity of CVE-2025-21836?: CVE-2025-21836 has not yet been assigned a CVSS score.
How to fix CVE-2025-21836?: To fix CVE-2025-21836, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-21836 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2025-21836 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-21836?: CVE-2025-21836 affects Linux Linux, Linux Linux.

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