Linux Kernel flush_tmregs_to_thread Function Denial of Service Vulnerability [CVE-2018-1091]

A vulnerability in the flush_tmregs_to_thread function of the Linux Kernel could allow a local attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability is due to a missing processor feature check and an erroneous use of transactional memory (TM) instructions in the core dump path by the affected software. This occurs when the flush_tmregs_to_thread function, as defined in the arch/powerpc/kernel/ptrace.c source code file of the affected software, is used. An attacker could exploit this vulnerability by using unprivileged userspace during a core dump on a POWER host. A successful exploit could trigger a guest kernel crash, resulting in a DoS condition on the system.

Kernel.org has confirmed the vulnerability and released software updates.

CVE number – CVE-2018-1091

Analysis
  • To exploit this vulnerability, an attacker must have local access to the targeted system. This access requirement may reduce the likelihood of a successful exploit.
Safeguards
  • Administrators are advised to apply the appropriate updates.

    Administrators are advised to allow only trusted users to access local systems.

    Administrators are advised to monitor affected systems.

Vendor Announcements
Fixed Software





Duncan Newell

Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.

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