CVE-2025-39793

linux: In the Linux kernel, the following vulnerability has been resolved: io_uring/memmap: cast nr_pages to size_t before...

CVE-2025-39793 is fixed in linux on 1 platform by DEBIAN-CVE-2025-39793 (version 6.16.3-1), released September 12, 2025. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
7.8
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0015
4th percentile

In the Linux kernel, the following vulnerability has been resolved: io_uring/memmap: cast nr_pages to size_t before shifting If the allocated size exceeds UINT_MAX, then it's necessary to cast the mr->nr_pages value to size_t to prevent it from overflowing. In practice this isn't much of a concern as the required memory size will have been validated upfront, and accounted to the user. And > 4GB sizes will be necessary to make the lack of a cast a problem, which greatly exceeds normal user locked_vm settings that are generally in the kb to mb range. However, if root is used, then accounting isn't done, and then it's possible to hit this issue.

Where it's fixed

ProductFixed inFixReleased
Linux
linux · Debian 14 6.16.3-1 DEBIAN-CVE-2025-39793 Sep 12, 2025

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