crypto/algif_skcipher.c in the Linux kernel before 4.4.2 does not verify that a setkey operation has been performed on an AF_ALG socket before an accept system call is processed, which allows local users to cause a denial of service (NULL pointer dereference and system crash) via a crafted application that does not supply a key, related to the lrw_crypt function in crypto/lrw.c.
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.2
http://www.openwall.com/lists/oss-security/2016/11/04/3
http://www.securityfocus.com/bid/94217
https://access.redhat.com/errata/RHSA-2017:1842
https://access.redhat.com/errata/RHSA-2017:2077
https://access.redhat.com/errata/RHSA-2017:2437
https://access.redhat.com/errata/RHSA-2017:2444
https://bugzilla.redhat.com/show_bug.cgi?id=1386286
https://github.com/torvalds/linux/commit/dd504589577d8e8e70f51f997ad487a4cb6c026f
https://groups.google.com/forum/#!msg/syzkaller/frb2XrB5aWk/xCXzkIBcDAAJ
Source: MITRE
Published: 2016-11-28
Updated: 2018-08-13
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