CVE-2025-21836

MEDIUM EPSS 11.9%
Published Mar 7, 20251y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Mar 7, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
11.9% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 5

VendorProductVersionRange
linuxlinux_kernel*≥5.19  –  <6.6.79
linuxlinux_kernel*≥6.7  –  <6.12.16
linuxlinux_kernel*≥6.13  –  <6.13.4
linuxlinux_kernel6.14any
linuxlinux_kernel6.14any

References 5

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

Remediation

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