CVE-2018-18397

Description

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.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=29ec90660d68bbdd69507c1c8b4e33aa299278b1

https://access.redhat.com/errata/RHBA-2019:0327

https://access.redhat.com/errata/RHSA-2019:0163

https://access.redhat.com/errata/RHSA-2019:0202

https://access.redhat.com/errata/RHSA-2019:0324

https://access.redhat.com/errata/RHSA-2019:0831

https://bugs.chromium.org/p/project-zero/issues/detail?id=1700

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.87

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.7

https://github.com/torvalds/linux/commit/29ec90660d68bbdd69507c1c8b4e33aa299278b1

https://usn.ubuntu.com/3901-1/

https://usn.ubuntu.com/3901-2/

https://usn.ubuntu.com/3903-1/

https://usn.ubuntu.com/3903-2/

Details

Risk Information

CVSS v2

CVSS v3