CVE-2025-21836

io_uring/kbuf: reallocate buf lists on upgrade

EPSS 0.2%

Vexday Risk Score

3Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS —EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

07 Mar 2025Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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.

Affected products

Linux · Linux

References

https://git.kernel.org/stable/c/146a185f6c05ee263db715f860620606303c4633 https://git.kernel.org/stable/c/2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4 https://git.kernel.org/stable/c/7d0dc28dae836caf7645fef62a10befc624dd17b https://git.kernel.org/stable/c/8802766324e1f5d414a81ac43365c20142e85603 https://u1f383.github.io/slides/talks/2025_Hexacon-Deja_Vu_in_Linux_io_uring_Breaking_Memory_Sharing_Again_After_Generations_of_Fixes.pdf