SB2017120207 - Denial of service in Linux Kernel

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Main Vulnerability Database SB2017120207

SB2017120207 - Denial of service in Linux Kernel

Published: December 2, 2017 Updated: December 8, 2017

Security Bulletin ID SB2017120207
Severity
Low
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 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-2017-15951)

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

The weakness exists due to the KEYS subsystem does not correctly synchronize the actions of updating versus finding a key in the "negative" state. A local attacker can make a specially crafted system calls, trigger race condition and cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

3) Null pointer dereference (CVE-ID: CVE-2017-15306)

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

The weakness exists due to NULL pointer dereference in the kvm_vm_ioctl_check_extension function in arch/powerpc/kvm/powerpc.c in the Linux kernel. A local attacker can make a KVM_CHECK_EXTENSION KVM_CAP_PPC_HTM ioctl call to /dev/kvm and cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

4) Null pointer dereference (CVE-ID: CVE-2017-15299)

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

The weakness exists due to the KEYS subsystem mishandles use of add_key for a key that already exists but is uninstantiated. A local attacker can supply specially crafted keys, trigger null pointer dereference and cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

5) 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