CVE-2018-10675 in Linux
Summary
by MITRE
The do_get_mempolicy function in mm/mempolicy.c in the Linux kernel before 4.12.9 allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via crafted system calls.
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Analysis
by VulDB Data Team • 03/08/2023
The vulnerability identified as CVE-2018-10675 resides within the Linux kernel's memory policy handling mechanism, specifically in the do_get_mempolicy function located in mm/mempolicy.c. This flaw represents a critical security issue that affects Linux kernel versions prior to 4.12.9, where local attackers can exploit improper memory management practices to either crash the system or potentially execute arbitrary code. The vulnerability manifests through crafted system calls that manipulate memory policy operations, creating conditions where freed memory regions are accessed beyond their intended lifecycle. This type of vulnerability falls under the category of use-after-free errors, which are classified as CWE-416 by the Common Weakness Enumeration framework and represent one of the most prevalent classes of memory corruption vulnerabilities in kernel space.
The technical implementation of this vulnerability involves the improper handling of memory references within the kernel's memory policy subsystem. When the do_get_mempolicy function processes certain system calls, it fails to properly validate or manage reference counts for memory policy structures, leading to scenarios where memory allocated to these structures can be freed while still being referenced by subsequent operations. This creates a race condition or memory management inconsistency that local attackers can leverage by carefully crafting system calls that trigger the vulnerable code path. The kernel's memory management subsystem, which is responsible for organizing and allocating memory across different nodes in NUMA architectures, becomes compromised when these structures are improperly managed, potentially allowing attackers to manipulate kernel memory layout or trigger memory corruption that could escalate to privilege escalation or system instability.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides local attackers with potential pathways to system compromise. While the primary effect is a use-after-free condition that can cause system crashes and denial of service, the underlying memory corruption issues create opportunities for more sophisticated attacks. Attackers could potentially exploit the memory corruption to manipulate kernel data structures, alter memory mappings, or even achieve privilege escalation depending on the specific conditions and memory layout at the time of exploitation. The vulnerability is particularly concerning because it affects the core memory management functionality of the kernel, which is fundamental to system operation and security. According to ATT&CK framework categorization, this vulnerability would be classified under privilege escalation techniques through kernel exploitation, specifically targeting the kernel's memory management subsystem.
Mitigation strategies for CVE-2018-10675 primarily focus on kernel version updates and system hardening measures. The most effective immediate solution is upgrading to Linux kernel version 4.12.9 or later, where the vulnerability has been addressed through proper memory management and reference counting mechanisms. System administrators should also implement kernel lockdown mechanisms and disable unnecessary memory policy features when not required. Additionally, monitoring for unusual system call patterns and implementing intrusion detection systems can help identify exploitation attempts. The fix implemented by the kernel developers involved correcting the reference counting logic within the mempolicy subsystem to ensure that memory structures remain valid throughout their intended usage period, preventing the conditions that led to the use-after-free scenario. Organizations should also consider implementing automated patch management processes to ensure timely deployment of kernel security updates and maintain comprehensive system monitoring to detect potential exploitation attempts.