CVE-2023-53401
📋 TL;DR
This CVE describes a race condition in the Linux kernel's memory management subsystem where concurrent access to stock->cached_objcg pointer can cause a NULL pointer dereference. This affects Linux systems running vulnerable kernel versions and can lead to kernel crashes or denial of service. The vulnerability was discovered by KCSAN (Kernel Concurrency Sanitizer) during testing.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially causing data loss or service disruption.
Likely Case
System instability or kernel crash requiring reboot, resulting in temporary service interruption.
If Mitigated
Minor performance impact from the race condition fix with no security compromise.
🎯 Exploit Status
Exploitation requires triggering a specific race condition between drain_all_stock and drain_obj_stock functions, which may be difficult to reliably achieve.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 33391c7e1a2ad612bf3922cc168cb09a46bbe236, 33d9490b27e5d8da4444aefd714a4f50189db978, or 3b8abb3239530c423c0b97e42af7f7e856e1ee96
Vendor Advisory: https://git.kernel.org/stable/c/33391c7e1a2ad612bf3922cc168cb09a46bbe236
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
No effective workaround
allThis is a kernel-level race condition that cannot be mitigated without patching.
🧯 If You Can't Patch
- Monitor systems for kernel panics or crashes and have recovery procedures ready
- Limit local user access and reduce concurrent memory-intensive operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version: uname -r and compare with distribution's security advisoriesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version after update and check that it includes the fix commits📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- System crash logs
- NULL pointer dereference errors in kernel logs
Network Indicators:
- None - this is a local kernel vulnerability
SIEM Query:
Search for kernel panic or oops messages containing 'obj_stock_flush_required' or 'drain_all_stock'