In the Linux kernel through 5.2.1 on the powerpc platform, when hardware transactional memory is disabled, a local user can cause a denial of service (TM Bad Thing exception and system crash) via a sigreturn() system call that sends a crafted signal frame. This affects arch/powerpc/kernel/signal_32.c and arch/powerpc/kernel/signal_64.c.
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00055.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00056.html
http://www.openwall.com/lists/oss-security/2019/07/30/1
https://git.kernel.org/torvalds/c/f16d80b75a096c52354c6e0a574993f3b0dfbdfe
https://lists.debian.org/debian-lts-announce/2019/08/msg00017.html
https://patchwork.ozlabs.org/patch/1133904/
https://seclists.org/bugtraq/2019/Aug/13
https://seclists.org/bugtraq/2019/Aug/18
https://seclists.org/bugtraq/2019/Aug/26
https://security.netapp.com/advisory/ntap-20190806-0001/
https://usn.ubuntu.com/4114-1/
https://usn.ubuntu.com/4115-1/
https://usn.ubuntu.com/4116-1/
Source: MITRE
Published: 2019-07-19
Updated: 2019-07-30
Type: CWE-399
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