CVE-2025-71292

Name	CVE-2025-71292
Description	In the Linux kernel, the following vulnerability has been resolved: jfs: nlink overflow in jfs_rename If nlink is maximal for a directory (-1) and inside that directory you perform a rename for some child directory (not moving from the parent), then the nlink of the first directory is first incremented and later decremented. Normally this is fine, but when nlink = -1 this causes a wrap around to 0, and then drop_nlink issues a warning. After applying the patch syzbot no longer issues any warnings. I also ran some basic fs tests to look for any regressions.
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	vulnerable
	bullseye (security)	5.10.251-5	vulnerable
	bookworm	6.1.170-3	fixed
	bookworm (security)	6.1.172-1	fixed
	trixie	6.12.86-1	fixed
	trixie (security)	6.12.90-1	fixed
	forky, sid	7.0.9-1	fixed

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

Package	Type	Release	Fixed Version
linux	source	bookworm	6.1.170-1
linux	source	trixie	6.12.85-1
linux	source	(unstable)	6.19.6-1

https://git.kernel.org/linus/9218dc26fd922b09858ecd3666ed57dfd8098da8 (7.0-rc1)