CVE-2021-47653
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's davinci vpif media driver. When the driver is unbound (removed), it fails to properly deregister platform devices, leading to memory corruption that could allow local attackers to escalate privileges or crash the system. This affects Linux systems using the affected kernel versions with the davinci vpif driver loaded.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation to root, kernel panic causing system crash, or potential remote code execution if combined with other vulnerabilities.
Likely Case
Local privilege escalation allowing an attacker with user access to gain root privileges on the affected system.
If Mitigated
Minimal impact if proper access controls prevent local user access or if the vulnerable driver is not loaded.
🎯 Exploit Status
Requires local access and knowledge of kernel exploitation techniques. No public exploit code is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in stable kernel versions via commits: 43acb728bbc4, 6512c3c39cb6, 9ffc602e14d7, b5a3bb7f6f16
Vendor Advisory: https://git.kernel.org/stable/c/43acb728bbc40169d2e2425e84a80068270974be
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 patch is applied by checking kernel version or examining the driver code.
🔧 Temporary Workarounds
Unload vulnerable driver
linuxPrevent exploitation by unloading the davinci vpif driver if not needed
modprobe -r davinci_vpif
Blacklist driver
linuxPrevent the driver from loading at boot
echo 'blacklist davinci_vpif' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict local user access to prevent potential privilege escalation
- Monitor for unusual kernel crashes or privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check if davinci_vpif driver is loaded: lsmod | grep davinci_vpifCheck Version:
uname -rVerify Fix Applied:
Check kernel version against patched versions from your distribution vendor📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes related to media/davinci drivers
- Unexpected privilege escalation
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Search for: 'kernel: BUG:' OR 'kernel: Oops:' OR 'davinci_vpif' in system logs