The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO_ ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file (if the user has read-only access to that file, and that file contains holes), related to fs/userfaultfd.c and mm/userfaultfd.c.
4.13.0-16.194.13.0-17.204.13.0-25.294.13.0-32.354.15.0-10.114.15.0-12.134.15.0-13.144.15.0-15.164.15.0-19.204.15.0-20.21+15 more4.15.0-46.493.11.0-12.194.2.0-16.194.4.0-1002.24.4.0-1001.104.15.0-1001.14.15.0-1003.34.15.0-1005.54.15.0-1006.64.15.0-1007.74.15.0-1009.94.15.0-1010.104.15.0-1011.114.15.0-1016.164.15.0-1017.17+9 more4.15.0-1033.354.15.0-1030.31~16.04.14.15.0-1031.33~16.04.14.15.0-1032.34~16.04.14.15.0-1033.35~16.04.14.15.0-1023.24~14.04.14.15.0-1030.31~14.04.14.15.0-1031.32~14.04.14.15.0-1032.33~14.04.24.15.0-1035.36~14.04.24.15.0-1036.38~14.04.24.15.0-1037.39~14.04.24.15.0-1039.41~14.04.24.15.0-1040.44~14.04.14.11.0-1009.94.11.0-1011.114.11.0-1013.134.11.0-1014.144.11.0-1015.154.11.0-1016.164.13.0-1005.74.13.0-1006.84.13.0-1007.94.13.0-1009.12+21 more4.15.0-1040.444.15.0-1002.24.15.0-1003.34.15.0-1004.44.15.0-1008.84.15.0-1009.94.15.0-1012.124.15.0-1013.134.15.0-1014.144.15.0-1018.184.15.0-1019.19+12 more4.18.0-1013.13~18.04.1Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:HA:NCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N