What’s Vulnerable › Vulnerabilities

CVE-2025-39822: io_uring/kbuf: fix signedness in this_len calculation

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-09-16 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: fix signedness in this_len calculation When importing and using buffers, buf->len is considered unsigned. However, buf->len is converted to signed int when committing. This can lead to unexpected behavior if the buffer is large enough to be interpreted as a negative value. Make min_t calculation unsigned.

Affected products

• Linux kernel: from 6.12 before 6.16.5; 6.17-rc1, 6.17-rc2, 6.17-rc3 — fixed in 6.16.5

How to fix

Upgrade to a fixed version: Linux kernel 6.16.5. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/c64eff368ac676e8540344d27a3de47e0ad90d21
• https://git.kernel.org/stable/c/f4f411c068402c370c4f9a9d4950a97af97bbbb1

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