CVE-2025-68186

Name	CVE-2025-68186
Description	In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches up The function ring_buffer_map_get_reader() is a bit more strict than the other get reader functions, and except for certain situations the rb_get_reader_page() should not return NULL. If it does, it triggers a warning. This warning was triggering but after looking at why, it was because another acceptable situation was happening and it wasn't checked for. If the reader catches up to the writer and there's still data to be read on the reader page, then the rb_get_reader_page() will return NULL as there's no new page to get. In this situation, the reader page should not be updated and no warning should trigger.
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)	5.10.247-1	fixed
	bookworm	6.1.148-1	fixed
	bookworm (security)	6.1.158-1	fixed
	trixie	6.12.57-1	vulnerable
	trixie (security)	6.12.48-1	vulnerable
	forky	6.17.11-1	fixed
	sid	6.17.12-1	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)	6.17.8-1

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/aa997d2d2a0b2e76f4df0f1f12829f02acb4fb6b (6.18-rc5)