CVE-2022-50555
📋 TL;DR
A null pointer dereference vulnerability in the Linux kernel's TIPC (Transparent Inter-Process Communication) subsystem allows local denial of service. When exploited, it causes kernel crashes in systems using TIPC networking. This affects Linux systems with TIPC enabled, typically in clustered or high-availability environments.
💻 Affected Systems
- Linux kernel
⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and complete denial of service, requiring physical or remote console access to reboot.
Likely Case
Local denial of service causing system instability or crashes when TIPC services are manipulated.
If Mitigated
Minimal impact if TIPC is disabled or systems are properly patched.
🎯 Exploit Status
Syzbot found and reported the crash. Exploitation requires local access to trigger the race condition.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 24b129aed8730e48f47d852d58d76825ab6f407c or later
Vendor Advisory: https://git.kernel.org/stable/c/24b129aed8730e48f47d852d58d76825ab6f407c
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify TIPC functionality if required.
🔧 Temporary Workarounds
Disable TIPC module
linuxPrevent loading of TIPC kernel module if not required
echo 'install tipc /bin/true' >> /etc/modprobe.d/disable-tipc.conf
rmmod tipc
Blacklist TIPC module
linuxBlacklist TIPC module to prevent automatic loading
echo 'blacklist tipc' >> /etc/modprobe.d/blacklist-tipc.conf
🧯 If You Can't Patch
- Disable TIPC functionality if not required for system operation
- Implement strict access controls to prevent unauthorized local users from accessing TIPC services
🔍 How to Verify
Check if Vulnerable:
Check if TIPC module is loaded: lsmod | grep tipc. If loaded and kernel version is unpatched, system is vulnerable.Check Version:
uname -rVerify Fix Applied:
Check kernel version is patched and TIPC module loads without issues. Monitor system logs for crashes.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KASAN null-ptr-deref errors in dmesg
- System crashes with tipc_topsrv_accept in stack trace
Network Indicators:
- Unusual TIPC connection attempts if monitoring network traffic
SIEM Query:
source="kernel" AND ("KASAN: null-ptr-deref" OR "tipc_topsrv_accept" OR "kernel panic")🔗 References
- https://git.kernel.org/stable/c/24b129aed8730e48f47d852d58d76825ab6f407c
- https://git.kernel.org/stable/c/32a3d4660b34ce49ac0162338ebe362098e2f5df
- https://git.kernel.org/stable/c/7a939503fc32bff4ed60800b73ff7fbb4aea2142
- https://git.kernel.org/stable/c/82cb4e4612c633a9ce320e1773114875604a3cce
- https://git.kernel.org/stable/c/ce69bdac2310152bb70845024d5d704c52aabfc3
- https://git.kernel.org/stable/c/cedb41664e27b2cae7e21487f1bee22dcd84037d
