CVE-2025-21686

Name	CVE-2025-21686
Description	In the Linux kernel, the following vulnerability has been resolved: io_uring/rsrc: require cloned buffers to share accounting contexts When IORING_REGISTER_CLONE_BUFFERS is used to clone buffers from uring instance A to uring instance B, where A and B use different MMs for accounting, the accounting can go wrong: If uring instance A is closed before uring instance B, the pinned memory counters for uring instance B will be decremented, even though the pinned memory was originally accounted through uring instance A; so the MM of uring instance B can end up with negative locked memory.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.226-1	fixed
	bookworm	6.1.123-1	fixed
	bookworm (security)	6.1.128-1	fixed
	trixie	6.12.12-1	fixed
	sid	6.12.15-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
linux	source	bullseye	(not affected)
linux	source	bookworm	(not affected)
linux	source	(unstable)	6.12.12-1

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/19d340a2988d4f3e673cded9dde405d727d7e248 (6.14-rc1)