Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused. This is fixed in the following kernel versions: 4.9.135, 4.14.78, 4.18.16, 4.19.
5.3.0-18.195.3.0-24.265.4.0-9.123.11.0-12.193.12.0-1.33.12.0-2.53.12.0-2.73.12.0-3.83.12.0-3.93.12.0-4.103.12.0-4.123.12.0-5.133.12.0-7.15+133 more3.13.0-165.2156.8.0-31.316.5.0-9.94.2.0-16.194.2.0-17.214.2.0-19.234.3.0-1.104.3.0-2.114.3.0-5.164.3.0-6.174.3.0-7.184.4.0-10.254.4.0-101.124+76 more4.4.0-142.1685.13.0-19.194.13.0-16.194.13.0-17.204.13.0-25.294.13.0-32.354.15.0-10.114.15.0-12.134.15.0-13.144.15.0-15.164.15.0-19.204.15.0-20.21+13 more4.15.0-44.474.15.0-1001.14.15.0-1003.34.15.0-1005.54.15.0-1006.64.15.0-1007.74.15.0-1009.94.15.0-1010.104.15.0-1011.114.15.0-1016.164.15.0-1017.17+8 more4.15.0-1032.346.8.0-1008.84.4.0-1002.24.4.0-1003.34.4.0-1005.54.4.0-1006.64.4.0-1009.94.4.0-1010.104.4.0-1011.114.4.0-1012.124.4.0-1014.144.4.0-1016.16+14 more4.4.0-1038.41Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:HCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H