CVE-2023-53423
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's objtool utility within the create_static_call_sections() function. The vulnerability occurs when strdup() allocates memory but fails to release it in error paths, potentially leading to resource exhaustion. This affects systems running vulnerable Linux kernel versions with objtool enabled.
💻 Affected Systems
- Linux Kernel
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
An attacker could repeatedly trigger the error path to cause memory exhaustion, leading to kernel panic or system instability, potentially resulting in denial of service.
Likely Case
Limited impact in most scenarios as objtool is typically used during kernel compilation rather than runtime, but could affect systems where objtool is actively used or during kernel build processes.
If Mitigated
With proper memory management controls and monitoring, the impact would be minimal as the leak occurs only in specific error conditions.
🎯 Exploit Status
Exploitation requires triggering specific error conditions in objtool's create_static_call_sections() function, which may not be easily accessible in production systems.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in git commits referenced in CVE description
Vendor Advisory: https://git.kernel.org/stable/c/3a75866a5ceff5d4fdd5471e06c4c4d03e0298b3
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from official kernel sources. 2. Recompile kernel if using custom build. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable objtool if not needed
allIf objtool functionality is not required for your use case, disable it during kernel configuration
During kernel configuration: CONFIG_STACK_VALIDATION=n
🧯 If You Can't Patch
- Monitor system memory usage for unusual patterns that might indicate memory leak exploitation
- Implement kernel memory usage limits and monitoring to detect potential resource exhaustion
🔍 How to Verify
Check if Vulnerable:
Check kernel version and configuration: 'uname -r' and verify if CONFIG_STACK_VALIDATION is enabled in kernel configCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to include the git commit fixes referenced in the CVE description📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages, memory allocation failures, system instability logs
Network Indicators:
- None - this is a local kernel vulnerability
SIEM Query:
Search for kernel panic messages, memory allocation failures, or objtool-related error messages in system logs🔗 References
- https://git.kernel.org/stable/c/3a75866a5ceff5d4fdd5471e06c4c4d03e0298b3
- https://git.kernel.org/stable/c/3da73f102309fe29150e5c35acd20dd82063ff67
- https://git.kernel.org/stable/c/a1368eaea058e451d20ea99ca27e72d9df0d16dd
- https://git.kernel.org/stable/c/a8f63d747bf7c983882a5ea7456a5f84ad3acad5
- https://git.kernel.org/stable/c/d131718d9c45d559951f57c4b88209ca407433c4
