CVE-2026-43376

Name	CVE-2026-43376
Description	In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free by using call_rcu() for oplock_info ksmbd currently frees oplock_info immediately using kfree(), even though it is accessed under RCU read-side critical sections in places like opinfo_get() and proc_show_files(). Since there is no RCU grace period delay between nullifying the pointer and freeing the memory, a reader can still access oplock_info structure after it has been freed. This can leads to a use-after-free especially in opinfo_get() where atomic_inc_not_zero() is called on already freed memory. Fix this by switching to deferred freeing using call_rcu().
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)	5.10.251-4	fixed
	bookworm	6.1.159-1	fixed
	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	bullseye	(not affected)
linux	source	bookworm	(not affected)
linux	source	trixie	6.12.85-1
linux	source	(unstable)	6.19.10-1

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/1dfd062caa165ec9d7ee0823087930f3ab8a6294 (7.0-rc4)