CVE-2022-49538
📋 TL;DR
This CVE describes a race condition vulnerability in the Linux kernel's ALSA sound subsystem where the input_dev pointer could become NULL while being accessed, causing a kernel NULL pointer dereference. This affects Linux systems using ASoC (ALSA System on Chip) audio drivers. The vulnerability can lead to system crashes or denial of service.
💻 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 →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 reboot.
Likely Case
System instability or crash when audio jack events occur concurrently with driver unregistration.
If Mitigated
Minor performance impact from mutex locking with no security impact when patched.
🎯 Exploit Status
Exploitation requires triggering specific race condition timing with audio events.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in stable kernel commits referenced in CVE
Vendor Advisory: https://git.kernel.org/stable/c/1b6a6fc5280e97559287b61eade2d4b363e836f2
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing fix. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable affected audio drivers
linuxTemporarily disable ASoC audio drivers that might trigger the race condition
modprobe -r <affected_driver>
echo 'blacklist <affected_driver>' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict local user access to systems with vulnerable kernels
- Monitor system logs for kernel panic events related to ALSA/ASoC
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with distribution security advisories. Vulnerable if using unpatched kernel with ASoC audio.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes commit 1b6a6fc5280e97559287b61eade2d4b363e836f2 or other referenced patches.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference in ALSA/ASoC subsystem
- System crash/reboot events
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "kernel panic" OR "ALSA" OR "ASoC")🔗 References
- https://git.kernel.org/stable/c/1b6a6fc5280e97559287b61eade2d4b363e836f2
- https://git.kernel.org/stable/c/582aea6084cc59fec881204f026816d1219f2348
- https://git.kernel.org/stable/c/5cc6f623f4818c7d7e9e966a45ebf324901ca9c5
- https://git.kernel.org/stable/c/74bab3bcf422593c582e47130aa8eb41ebb2dc09
- https://git.kernel.org/stable/c/8487a88136d54a1a4d3f26f1399685db648ab879
- https://git.kernel.org/stable/c/9e6a73b0c0f2014eb89249fb1640c5a3d58221c4
- https://git.kernel.org/stable/c/c093b62c40027c21d649c5534ad7aa3605a99b00
- https://git.kernel.org/stable/c/e2b8681769f6e205382f026b907d28aa5ec9d59a
- https://git.kernel.org/stable/c/f68bed124c7699e23ffb4ce4fcc84671e9193cde
