The keyctl_read_key function in security/keys/keyctl.c in the Key Management subcomponent in the Linux kernel before 4.13.5 does not properly consider that a key may be possessed but negatively instantiated, which allows local users to cause a denial of service (OOPS and system crash) via a crafted KEYCTL_READ operation.
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.13.5
https://access.redhat.com/errata/RHSA-2018:0151
https://bugzilla.redhat.com/show_bug.cgi?id=1493435
https://github.com/torvalds/linux/commit/37863c43b2c6464f252862bf2e9768264e961678
https://lkml.org/lkml/2017/9/18/764
Source: MITRE
Published: 2017-10-12
Updated: 2018-03-16
Type: CWE-476
Base Score: 4.9
Vector: AV:L/AC:L/Au:N/C:N/I:N/A:C
Impact Score: 6.9
Exploitability Score: 3.9
Severity: MEDIUM
Base Score: 5.5
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 1.8
Severity: MEDIUM