CVE-2022-49935
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's DMA buffer reservation system allows attackers with local access to potentially execute arbitrary code or crash the system. This affects Linux systems using the dma-buf subsystem for GPU and hardware acceleration. The vulnerability occurs when userspace can manipulate fence ordering to trigger memory corruption.
💻 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 →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 to kernel-level code execution, potentially leading to complete system compromise.
Likely Case
Kernel panic or system crash causing denial of service.
If Mitigated
No impact if patched or if dma-buf subsystem is not in use.
🎯 Exploit Status
Requires local access and knowledge of dma-buf subsystem. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits a3f7c10a269d5b77dd5822ade822643ced3057f0 or c4c798fe98adceb642050819cb57cbc8f5c27870
Vendor Advisory: https://git.kernel.org/stable/c/a3f7c10a269d5b77dd5822ade822643ced3057f0
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable dma-buf subsystem
linuxRemove or disable dma-buf module if not required (will break GPU/hardware acceleration)
modprobe -r dma_buf
echo 'blacklist dma_buf' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict local user access to systems using dma-buf functionality
- Implement strict application sandboxing to limit potential exploit vectors
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from kernel git repositoryCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or is newer than vulnerable versions📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- OOPs messages related to dma_resv or dma-buf
- System crash dumps
Network Indicators:
- None - local exploit only
SIEM Query:
source="kernel" AND ("dma_resv" OR "dma-buf" OR "use-after-free")