CVE-2025-39816 — io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths
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 fro…
Published: 2025-09-16 · CVSS: 5.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7