SB2017121442 - SUSE Linux update for the Linux Kernel

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Race condition (CVE-ID: CVE-2017-1000405)

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a race condition within touch_pmd() function in mmhugemem.c file when handling THPs. A local user can read read-only huge pages using the get_user_pages() function and overwrite arbitrary huge pages and files mapped via THP.

Successful exploitation of the vulnerability may allow an attacker to perform a denial of service (DoS) attack.

This vulnerability is a result of patch against a another privilege escalation vulnerability in Linux kernel known as Dirty Cow (CVE-2016-5195).

2) Race condition (CVE-ID: CVE-2017-10661)

The vulnerability allows a local attacker to gain elevated privileges or cause DoS condition on the target system.

The weakness exists due to race condition in fs/timerfd.c in the Linux kernel. A local attacker can use simultaneous file-descriptor operations, leverage improper might_cancel queueing, trigger list corruption or use-after-free and cause the service to crash or execute arbitrary code with root privileges.

3) Use-after-free error (CVE-ID: CVE-2017-16939)

The vulnerability allows a local attacker to cause DoS condition on the target system.

The weakness exists in the XFRM dump policy implementation in net/xfrm/xfrm_user.c in the Linux kernel due to use-after-free error. A local attacker can make a specially crafted SO_RCVBUF setsockopt system call in conjunction with XFRM_MSG_GETPOLICY Netlink messages, trigger memory corruption and cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

Remediation

Install update from vendor's website.

References

• https://lists.opensuse.org/opensuse-security-announce/2017-12/msg00033.html