CVE-2024-35985

Name	CVE-2024-35985
Description	In the Linux kernel, the following vulnerability has been resolved: sched/eevdf: Prevent vlag from going out of bounds in reweight_eevdf() It was possible to have pick_eevdf() return NULL, which then causes a NULL-deref. This turned out to be due to entity_eligible() returning falsely negative because of a s64 multiplcation overflow. Specifically, reweight_eevdf() computes the vlag without considering the limit placed upon vlag as update_entity_lag() does, and then the scaling multiplication (remember that weight is 20bit fixed point) can overflow. This then leads to the new vruntime being weird which then causes the above entity_eligible() to go side-ways and claim nothing is eligible. Thus limit the range of vlag accordingly. All this was quite rare, but fatal when it does happen.
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)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.226-1	fixed
	bookworm	6.1.115-1	fixed
	bookworm (security)	6.1.112-1	fixed
	trixie	6.11.7-1	fixed
	sid	6.11.9-1	fixed

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

Package	Type	Release	Fixed Version
linux	source	buster	(not affected)
linux	source	bullseye	(not affected)
linux	source	bookworm	(not affected)
linux	source	(unstable)	6.8.9-1

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
[buster] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/1560d1f6eb6b398bddd80c16676776c0325fe5fe (6.9-rc6)