CVE-2026-43458

Name	CVE-2026-43458
Description	In the Linux kernel, the following vulnerability has been resolved: serial: caif: hold tty->link reference in ldisc_open and ser_release A reproducer triggers a KASAN slab-use-after-free in pty_write_room() when caif_serial's TX path calls tty_write_room(). The faulting access is on tty->link->port. Hold an extra kref on tty->link for the lifetime of the caif_serial line discipline: get it in ldisc_open() and drop it in ser_release(), and also drop it on the ldisc_open() error path. With this change applied, the reproducer no longer triggers the UAF in my testing.
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)	5.10.251-4	vulnerable
	bookworm	6.1.159-1	vulnerable
	bookworm (security)	6.1.170-1	fixed
	trixie	6.12.73-1	vulnerable
	trixie (security)	6.12.86-1	fixed
	forky	6.19.14-1	fixed
	sid	7.0.4-1	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)	6.19.10-1

https://git.kernel.org/linus/288598d80a068a0e9281de35bcb4ce495f189e2a (7.0-rc4)