CVE-2022-50295
📋 TL;DR
This is a NULL pointer dereference vulnerability in the Linux kernel's io_uring subsystem that allows local attackers to cause a kernel panic (denial of service) by triggering a crash in the io_msg_send_fd() function. It affects Linux systems with vulnerable kernel versions where io_uring is enabled. The vulnerability requires local access to exploit.
💻 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 attacker causes kernel panic leading to system crash and denial of service, potentially requiring physical or remote console access to reboot.
Likely Case
Local user or process triggers kernel panic resulting in system crash and temporary unavailability.
If Mitigated
System remains stable with proper access controls preventing unauthorized local users from exploiting the vulnerability.
🎯 Exploit Status
Exploitation requires local access and knowledge of io_uring operations. The vulnerability was discovered through fuzzing (syzkaller).
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel commit 0163e04ea64cc3dfaa12390286e5f2f481c3b2e3 and backports to stable branches
Vendor Advisory: https://git.kernel.org/stable/c/0163e04ea64cc3dfaa12390286e5f2f481c3b2e3
Restart Required: Yes
Instructions:
1. Update to a patched kernel version from your distribution vendor. 2. Reboot the system to load the new kernel. 3. Verify the fix is applied by checking kernel version.
🔧 Temporary Workarounds
Disable io_uring module
LinuxPrevent loading of the io_uring kernel module to mitigate the vulnerability
echo 'blacklist io_uring' >> /etc/modprobe.d/blacklist-io_uring.conf
rmmod io_uring
🧯 If You Can't Patch
- Restrict local user access to prevent unauthorized users from running io_uring operations
- Implement strict process isolation and containerization to limit impact scope
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from your distribution. Vulnerable if using kernel versions before the fix commit.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commit 0163e04ea64cc3dfaa12390286e5f2f481c3b2e3 or later📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in system logs
- NULL pointer dereference errors in kernel logs
- System crash/reboot events
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "Kernel panic" OR "io_msg_send_fd")