CVE-2022-50515
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's AMD GPU driver. When the hpd_rx_irq_create_workqueue() function fails to create work queues for handling hotplug detection interrupts, it doesn't properly clean up previously allocated resources, leading to kernel memory exhaustion over time. This affects Linux systems with AMD graphics hardware using the affected kernel versions.
💻 Affected Systems
- Linux kernel with AMD GPU driver (drm/amdgpu)
⚠️ Risk & Real-World Impact
Worst Case
Sustained exploitation could lead to kernel memory exhaustion, causing system instability, denial of service, or potential kernel panic/crash.
Likely Case
Memory leak gradually consumes kernel memory, potentially leading to system performance degradation or instability over time.
If Mitigated
With proper monitoring and timely patching, impact is limited to temporary performance issues before remediation.
🎯 Exploit Status
Exploitation requires triggering the specific error condition in the workqueue creation function, which may require specific hardware/software conditions or repeated hotplug events.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 3ba3814c00a4817eb1cd31eff08d921c40e5f3a4, 600de40ed50c8b5ecb9c7a4f41eb882066c15a00, 7136f956c73c4ba50bfeb61653dfd6a9669ea915, 8b8da09da2701330e7f2c371655887e3d7defe90
Vendor Advisory: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3ba3814c00a4817eb1cd31eff08d921c40e5f3a4
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable AMD GPU driver
linuxPrevent loading of the vulnerable amdgpu kernel module
echo 'blacklist amdgpu' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot
Limit hotplug events
linuxReduce frequency of display hotplug events that could trigger the vulnerability
🧯 If You Can't Patch
- Monitor kernel memory usage for unusual increases using tools like 'free', 'top', or '/proc/meminfo'
- Implement system monitoring to detect memory exhaustion and automatically restart affected services
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if amdgpu module is loaded: 'uname -r' and 'lsmod | grep amdgpu'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is newer than fix commits and check dmesg for any memory leak warnings related to amdgpu📡 Detection & Monitoring
Log Indicators:
- Kernel oom-killer messages
- Memory allocation failures in dmesg
- Repeated amdgpu module errors
SIEM Query:
source="kernel" AND ("oom" OR "out of memory" OR "amdgpu" AND "failed")