CVE-2025-21836

Name	CVE-2025-21836
Description	In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: reallocate buf lists on upgrade IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it was created for legacy selected buffer and has been emptied. It violates the requirement that most of the field should stay stable after publish. Always reallocate it instead.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, 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)	5.10.244-1	fixed
	bookworm	6.1.148-1	vulnerable
	bookworm (security)	6.1.153-1	vulnerable
	trixie	6.12.43-1	fixed
	trixie (security)	6.12.48-1	fixed
	forky, sid	6.16.12-2	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	bullseye	(not affected)
linux	source	(unstable)	6.12.16-1

[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/8802766324e1f5d414a81ac43365c20142e85603 (6.14-rc3)