CVE-2026-97562

Name	CVE-2026-97562
Description	In the Linux kernel, the following vulnerability has been resolved: smb: client: pin DFS superblock in iterator callback tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super() takes its active reference only after iterate_supers_type() has dropped s_umount and its passive reference. Concurrent DFS automount expiry can therefore free the superblock before cifs_sb_active() uses it. A deterministic KASAN test reproduces the race as: BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80 The same test passes with this change applied. Take the active reference in the callback while iterate_supers_type() still holds s_umount shared. cifs_put_tcp_super() remains the matching release.
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)
References	DLA-4817-1, DSA-6528-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bookworm	6.1.176-1	vulnerable
	bookworm (security)	6.1.187-1	vulnerable
	trixie	6.12.107-1	vulnerable
	trixie (security)	6.12.111-1	fixed
	forky	7.2.9-1	fixed
	sid	7.2.10-1	fixed
linux-6.12 (PTS)	bookworm (security)	6.12.111-1~deb12u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	trixie	6.12.111-1	DSA-6528-1
linux	source	(unstable)	7.2.7-1
linux-6.12	source	bookworm	6.12.111-1~deb12u1	DLA-4817-1

https://git.kernel.org/linus/d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818 (7.3-rc3)