Bug 2402718 (CVE-2025-39963)

Summary: CVE-2025-39963 kernel: io_uring: fix incorrect io_kiocb reference in io_link_skb
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-10-09 13:01:41 UTC 
In the Linux kernel, the following vulnerability has been resolved:

io_uring: fix incorrect io_kiocb reference in io_link_skb

In io_link_skb function, there is a bug where prev_notif is incorrectly
assigned using 'nd' instead of 'prev_nd'. This causes the context
validation check to compare the current notification with itself instead
of comparing it with the previous notification.

Fix by using the correct prev_nd parameter when obtaining prev_notif.
Comment 1 Alexander B 2025-12-23 14:39:57 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025100917-CVE-2025-39963-b0ff@gregkh/T