Linux Kernel fs/xfs/xfs_aops.c Local Denial of Service Vulnerability [CVE-2016-10741]
CVE Number – CVE-2016-10741
A vulnerability in the fs/xfs/xfs_aops.c source code file of the Linux Kernel could allow a local attacker to cause a denial of service (DoS) condition on a targeted system.
The vulnerability exists because the BUG_ON function, as defined in the fs/xfs/xfs_aops.c source code file of the affected software, handles a race condition between a direct I/O read and memory-mapped I/O write to a hole in a file, which should result in an I/O failure instead. An attacker could exploit the vulnerability by accessing the system and executing an application that submits malicious system calls to the affected software. An exploit could cause the system to crash, resulting in a DoS condition. Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.
Kernel.org has confirmed the vulnerability and released software updates.
Analysis
- To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement could 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 allow only privileged users to access administration or management systems.
Administrators are advised to monitor critical systems.
Vendor Announcements
- Kernel.org has released a changelog at the following link: ChangeLog-4.9.3 commit 04197b341f23b908193308b8d63d17ff23232598
Fixed Software
- Kernel.org has released software updates at the following links: Kernel 4.9.3 or later and xfs: don’t BUG() on mixed direct and mapped I/O
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.