Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths Since the buffers are mapped from userspace, it is prudent to use READ_ONCE() to read the value into a local variable, and use that for any other actions taken. Having a stable read of the buffer length avoids worrying about it changing after checking, or being read multiple times. Similarly, the buffer may well change in between it being picked and being committed. Ensure the looping for incremental ring buffer commit stops if it hits a zero sized buffer, as no further progress can be made at that point.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.12, < 6.12.49 |
References
- https://git.kernel.org/stable/c/390a61d284e1ced088d43928dfcf6f86fffdd780Patch
- https://git.kernel.org/stable/c/695673eb5711ee5eb1769481cf1503714716a7d1Patch
- https://git.kernel.org/stable/c/91f262ea2a76a02d9e37dba6637cfe6feebb20a8
- https://git.kernel.org/stable/c/98b6fa62c84f2e129161e976a5b9b3cb4ccd117bPatch
FAQ
What is CVE-2025-39816?
CVE-2025-39816 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths Since the buffers are mapped from userspace, it is prud...
How severe is CVE-2025-39816?
CVE-2025-39816 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-39816?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.