What is CVE-2017-18257?

CVE-2017-18257 is a medium-severity vulnerability in Linux Kernel, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2018-04-04.

How severe is CVE-2017-18257?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Integer overflow in Linux Kernel

CVE-2017-18257

The __get_data_block function in fs/f2fs/data.c in the Linux kernel before 4.11 allows local users to cause a denial of service (integer overflow and loop) via crafted use of the open and fallocate system calls with an FS_IOC_FIEMAP ioctl.

Vulnerability class: Integer Overflow

Published 2018-04-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (29.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.000

Affected products

Linux Kernel
Debian Linux — versions 9.0

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

usn.ubuntu.com/3696-1/ (vendor-advisory)
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/ (Patch)
github.com/torvalds/linux/commit/b86e33075ed1909d8002745b56ecf73b833db143 (Patch)
www.debian.org/security/2018/dsa-4188 (vendor-advisory, Third Party Advisory)
usn.ubuntu.com/3696-2/ (vendor-advisory)

Frequently asked questions

What is CVE-2017-18257?: CVE-2017-18257 is a medium-severity vulnerability in Linux Kernel, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2018-04-04.
How severe is CVE-2017-18257?: Medium severity. CVSS v3 base score is 5.5 out of 10.