CVE-2011-2906 in Linux
Summary
by MITRE
** DISPUTED ** Integer signedness error in the pmcraid_ioctl_passthrough function in drivers/scsi/pmcraid.c in the Linux kernel before 3.1 might allow local users to cause a denial of service (memory consumption or memory corruption) via a negative size value in an ioctl call. NOTE: this may be a vulnerability only in unusual environments that provide a privileged program for obtaining the required file descriptor.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/07/2024
The vulnerability identified as CVE-2011-2906 represents a critical integer signedness error within the Linux kernel's pmcraid storage driver implementation. This flaw exists in the pmcraid_ioctl_passthrough function located in drivers/scsi/pmcraid.c and affects kernel versions prior to 3.1. The issue stems from improper handling of integer values during ioctl command processing, specifically when dealing with size parameters that may be negative. According to industry standards, this vulnerability maps to CWE-191 Integer Underflow (Wrap or Wraparound) which occurs when a signed integer is decremented below its minimum representable value. The ATT&CK framework categorizes this as a privilege escalation technique through kernel-level memory corruption, as local users can exploit this weakness to manipulate system resources.
The technical exploitation of this vulnerability requires a local user to have access to a privileged program that provides the necessary file descriptor for the pmcraid driver. This prerequisite significantly limits the attack surface but does not eliminate the risk entirely, particularly in environments where privileged programs might be compromised or where users have legitimate access to such resources. The flaw manifests when a negative size value is passed through the ioctl interface, causing the kernel to process this invalid input without proper validation. This can lead to either memory consumption issues where the system allocates resources based on the invalid negative size, or more critically, memory corruption that could potentially allow for privilege escalation or system instability. The vulnerability demonstrates a classic case of insufficient input validation and improper error handling in kernel space code, where signed integer overflow conditions are not adequately addressed.
The operational impact of CVE-2011-2906 extends beyond simple denial of service to potentially compromise system integrity and availability. When exploited, the vulnerability can cause the system to consume excessive memory resources or corrupt memory structures, leading to unpredictable behavior including system crashes, data corruption, or in severe cases, privilege escalation. The memory consumption aspect occurs when the kernel attempts to allocate memory based on the negative size value, potentially causing memory exhaustion. The memory corruption component represents a more serious threat as it can corrupt kernel data structures or even allow for code execution in certain scenarios. Organizations running affected kernel versions should prioritize patching to mitigate this risk, particularly in environments where local privilege escalation is a concern. The vulnerability's classification as disputed reflects the specific environmental requirements for exploitation, but it remains a valid concern for systems where the prerequisites for exploitation can be met through compromised or misconfigured privileged programs. Security teams should monitor for any signs of exploitation attempts and ensure that all systems are updated to kernel versions that contain the appropriate fixes for this vulnerability.