CVE-2022-49199
📋 TL;DR
This CVE-2022-49199 is an integer underflow vulnerability in the Linux kernel's RDMA (Remote Direct Memory Access) subsystem. It allows local attackers to trigger memory corruption by passing negative values to the nldev_stat_set_counter_dynamic_doit() function. Systems running vulnerable Linux kernel versions with RDMA enabled are affected.
💻 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
Local privilege escalation leading to kernel panic, system crash, or arbitrary code execution with kernel privileges.
Likely Case
Local denial of service through kernel panic or system instability.
If Mitigated
Minimal impact if RDMA is disabled or proper access controls restrict local user privileges.
🎯 Exploit Status
Requires local access and knowledge of RDMA interfaces. No public exploits known as of this analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in stable kernel commits: 2a495ef04d5f, 87e0eacb176f, f6dd8669b829
Vendor Advisory: https://git.kernel.org/stable/c/2a495ef04d5f42e6f00eb2bec1ee9075e3d5a771
Restart Required: Yes
Instructions:
1. Update to a kernel version containing the fix commits. 2. Check with your Linux distribution for security updates. 3. Reboot the system after kernel update.
🔧 Temporary Workarounds
Disable RDMA module
linuxPrevent loading of RDMA kernel modules if not required
echo 'install rdma_cm /bin/false' >> /etc/modprobe.d/disable-rdma.conf
echo 'install ib_core /bin/false' >> /etc/modprobe.d/disable-rdma.conf
update-initramfs -u
🧯 If You Can't Patch
- Restrict local user access to systems with vulnerable kernels
- Disable RDMA functionality if not required for operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if RDMA modules are loaded: 'lsmod | grep -i rdma' and 'uname -r'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check that RDMA modules are either not loaded or system is patched with the fix commits📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- System crash dumps
- Unexpected RDMA-related errors in dmesg
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Search for kernel panic events or RDMA module loading anomalies