CVE-2024-26878

Name	CVE-2024-26878
Description	In the Linux kernel, the following vulnerability has been resolved: quota: Fix potential NULL pointer dereference Below race may cause NULL pointer dereference P1 P2 dquot_free_inode quota_off drop_dquot_ref remove_dquot_ref dquots = i_dquot(inode) dquots = i_dquot(inode) srcu_read_lock dquots[cnt]) != NULL (1) dquots[type] = NULL (2) spin_lock(&dquots[cnt]->dq_dqb_lock) (3) .... If dquot_free_inode(or other routines) checks inode's quota pointers (1) before quota_off sets it to NULL(2) and use it (3) after that, NULL pointer dereference will be triggered. So let's fix it by using a temporary pointer to avoid this issue.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, 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)	buster	4.19.249-2	vulnerable
	buster (security)	4.19.304-1	vulnerable
	bullseye	5.10.209-2	vulnerable
	bullseye (security)	5.10.205-2	vulnerable
	bookworm	6.1.76-1	vulnerable
	bookworm (security)	6.1.85-1	fixed
	trixie	6.6.15-2	vulnerable
	sid	6.7.12-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	bookworm	6.1.85-1
linux	source	(unstable)	6.7.12-1

https://git.kernel.org/linus/d0aa72604fbd80c8aabb46eda00535ed35570f1f (6.9-rc1)