CVE-2026-72213

Status: UPDATED  |  Advisory ID: CVE-2026-72213

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

mm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch

In alloc_hugetlb_folio(), a single h_cg pointer is used for both the rsvd

and non-rsvd hugetlb cgroup charges. When map_chg is set,

hugetlb_cgroup_charge_cgroup_rsvd() stores the charged cgroup in h_cg, but

the immediately following hugetlb_cgroup_charge_cgroup() overwrites h_cg

with the non-rsvd cgroup pointer.

As a result, hugetlb_cgroup_commit_charge_rsvd() stores the wrong

(non-rsvd) cgroup pointer into the folio's rsvd slot.

When the folio is later freed, free_huge_folio() unconditionally calls

both hugetlb_cgroup_uncharge_folio() and

hugetlb_cgroup_uncharge_folio_rsvd(). The rsvd uncharge reads back the

wrong cgroup from the folio and decrements a counter that was never

charged for that cgroup, causing a page_counter underflow:

page_counter underflow: -512 nr_pages=512

WARNING: mm/page_counter.c:61 at page_counter_cancel

Fix this by introducing a separate h_cg_rsvd pointer exclusively for the

rsvd charge path, keeping the rsvd and non-rsvd charges fully independent

through their charge, commit, and error uncharge paths. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References