CVEvulnerability

CVE-2024-36943

4.7 MEDIUM Published 2024-05-30 Modified 2026-08-04 Official page ↗
Status
Modified
Published
2024-05-30
Last modified
2026-08-04
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
7.3 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
CVSS 3.1 ([email protected])
4.7 MEDIUM — CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Description

In the Linux kernel, the following vulnerability has been resolved: fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan make_uffd_wp_pte() was previously doing: pte = ptep_get(ptep); ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte); But if another thread accessed or dirtied the pte between the first 2 calls, this could lead to loss of that information. Since ptep_modify_prot_start() gets and clears atomically, the following is the correct pattern and prevents any possible race. Any access after the first call would see an invalid pte and cause a fault: pte = ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte);

Affected configurations

• linux linux kernel (>= 6.7 < 6.8.10) • linux linux kernel 6.9

References