An issue was discovered in __split_huge_pmd in mm/huge_memory.c in the Linux kernel before 5.7.5. The copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check, aka CID-c444eb564fb1.
5.13.0-19.193.11.0-12.196.11.0-8.86.5.0-9.94.2.0-16.194.2.0-17.214.2.0-19.234.3.0-1.104.3.0-2.114.3.0-5.164.3.0-6.174.3.0-7.184.4.0-2.165.3.0-18.195.3.0-24.265.4.0-18.225.4.0-21.255.4.0-24.285.4.0-25.295.4.0-26.305.4.0-28.325.4.0-29.335.4.0-31.35+6 more5.4.0-45.494.13.0-16.194.13.0-17.204.13.0-25.294.13.0-32.354.15.0-10.114.15.0-101.1024.15.0-106.1074.15.0-108.1094.15.0-109.1104.15.0-111.112+44 more4.15.0-115.1165.13.0-1005.64.4.0-1002.24.4.0-1001.10Exploitability
AV:LAC:HPR:LUI:NScope
S:UImpact
C:HI:HA:HCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H