Bug 2419953 (CVE-2025-40291)

Summary: CVE-2025-40291 kernel: io_uring: fix regbuf vector size truncation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-12-08 07:11:27 UTC 
In the Linux kernel, the following vulnerability has been resolved:

io_uring: fix regbuf vector size truncation

There is a report of io_estimate_bvec_size() truncating the calculated
number of segments that leads to corruption issues. Check it doesn't
overflow "int"s used later. Rough but simple, can be improved on top.
Comment 1 TEJ RATHI 2025-12-08 14:34:43 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025120815-CVE-2025-40291-8752@gregkh/T