CVE-2022-49494
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Cadence NAND driver of the Linux kernel. If exploited, it could cause a kernel panic or system crash on systems using affected Cadence NAND controllers. The vulnerability affects Linux systems with specific hardware configurations.
💻 Affected Systems
- Linux kernel with Cadence NAND driver
📦 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
Kernel panic leading to system crash and denial of service, potentially requiring physical access to restart the system.
Likely Case
System crash or kernel panic when the vulnerable driver code path is triggered, resulting in temporary denial of service.
If Mitigated
No impact if the vulnerable driver is not loaded or the specific hardware is not present.
🎯 Exploit Status
Exploitation requires triggering the vulnerable code path in the Cadence NAND driver, which typically requires specific hardware and driver loading conditions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel versions with commits 069af5e27c1b0f7677ef76d8d3102e503ca4f80b or later
Vendor Advisory: https://git.kernel.org/stable/c/069af5e27c1b0f7677ef76d8d3102e503ca4f80b
Restart Required: Yes
Instructions:
1. Update to a patched Linux 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 or examining the driver source.
🔧 Temporary Workarounds
Disable Cadence NAND driver
linuxPrevent loading of the vulnerable driver module if not needed
echo 'blacklist cadence_nand' >> /etc/modprobe.d/blacklist.conf
rmmod cadence_nand
🧯 If You Can't Patch
- Ensure the Cadence NAND driver is not loaded if the hardware is not present
- Implement strict access controls to prevent local users from triggering the vulnerable code path
🔍 How to Verify
Check if Vulnerable:
Check if the cadence_nand module is loaded: lsmod | grep cadence_nand. If loaded and kernel version is unpatched, system is vulnerable.Check Version:
uname -rVerify Fix Applied:
Check kernel version is patched: uname -r should show version with fix commits. Verify cadence_nand module loads without issues.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- NULL pointer dereference errors in kernel logs
Network Indicators:
- None - this is a local kernel vulnerability
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "kernel panic" OR "cadence_nand")🔗 References
- https://git.kernel.org/stable/c/069af5e27c1b0f7677ef76d8d3102e503ca4f80b
- https://git.kernel.org/stable/c/0cfee868b89ffa945f3d535ee5c985cb40c5a0f8
- https://git.kernel.org/stable/c/13b60d3dc84b47307669edb66b633b18466014b4
- https://git.kernel.org/stable/c/81f1ddffdc22ca5789e33b9d4712914e302090c1
- https://git.kernel.org/stable/c/a28ed09dafee20da51eb26452950839633afd824
