CVE-2024-39473
📋 TL;DR
A NULL pointer dereference vulnerability in the Linux kernel's Sound Open Firmware (SOF) subsystem allows local attackers to cause a kernel panic or system crash. This affects systems using SOF for audio processing with specifically crafted audio topology configurations. The vulnerability requires local access to trigger.
💻 Affected Systems
- Linux kernel with SOF (Sound Open Firmware) subsystem enabled
📦 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 denial of service (system crash), potentially causing data loss or service disruption.
Likely Case
Local denial of service through kernel panic when malicious audio topology is loaded.
If Mitigated
Minimal impact with proper access controls preventing local users from loading custom audio topologies.
🎯 Exploit Status
Requires local access and ability to load specifically crafted audio topology configurations. Not trivial to exploit without understanding SOF audio subsystem.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 9e16f17a2a0e97b43538b272e7071537a3e03368, e3ae00ee238bce6cfa5ad935c921181c14d18fd6, ffa077b2f6ad124ec3d23fbddc5e4b0ff2647af8
Vendor Advisory: https://git.kernel.org/stable/c/9e16f17a2a0e97b43538b272e7071537a3e03368
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check your distribution's security advisories for patched kernel packages. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable SOF subsystem
linuxDisable Sound Open Firmware subsystem if not required for audio functionality
modprobe -r snd_sof
echo 'blacklist snd_sof' >> /etc/modprobe.d/blacklist.conf
Restrict audio topology loading
linuxImplement access controls to prevent unauthorized users from loading custom audio topologies
chmod 644 /sys/class/sound/controlC*/topology
setfacl -m u:root:rw /sys/class/sound/controlC*/topology
🧯 If You Can't Patch
- Implement strict access controls to prevent local users from loading custom audio topologies
- Monitor system logs for kernel panic events related to SOF subsystem
🔍 How to Verify
Check if Vulnerable:
Check if SOF subsystem is loaded: lsmod | grep snd_sof. Check kernel version: uname -r and compare with patched versions from your distribution.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits. Check with: grep -r '9e16f17a2a0e97b43538b272e7071537a3e03368' /usr/src/linux-headers-$(uname -r)/📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- NULL pointer dereference errors mentioning SOF or ipc4-topology
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kern.log" AND "NULL pointer dereference" AND ("SOF" OR "ipc4-topology")🔗 References
- https://git.kernel.org/stable/c/9e16f17a2a0e97b43538b272e7071537a3e03368
- https://git.kernel.org/stable/c/e3ae00ee238bce6cfa5ad935c921181c14d18fd6
- https://git.kernel.org/stable/c/ffa077b2f6ad124ec3d23fbddc5e4b0ff2647af8
- https://git.kernel.org/stable/c/9e16f17a2a0e97b43538b272e7071537a3e03368
- https://git.kernel.org/stable/c/e3ae00ee238bce6cfa5ad935c921181c14d18fd6
- https://git.kernel.org/stable/c/ffa077b2f6ad124ec3d23fbddc5e4b0ff2647af8
