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.
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.
Metrics
Affected Vendors & Products
No data.
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 16 Sep 2025 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths | |
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-09-16T13:00:17.026Z
Reserved: 2025-04-16T07:20:57.138Z
Link: CVE-2025-39816
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-09-16T13:15:56.790
Modified: 2025-09-16T13:15:56.790
Link: CVE-2025-39816
Redhat
No data.
OpenCVE Enrichment
No data.