CVE-2026-23155
📋 TL;DR
This CVE addresses a kernel panic vulnerability in the Linux kernel's CAN (Controller Area Network) USB driver (gs_usb). The issue occurs when the driver attempts to print an error message after a failed USB request block (URB) resubmission, potentially dereferencing an uninitialized netdev pointer. This affects systems using the gs_usb CAN driver with vulnerable kernel versions.
💻 Affected Systems
- Linux kernel with gs_usb CAN driver
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially disrupting CAN bus communications in critical systems like automotive, industrial control, or embedded devices.
Likely Case
System crash or instability when specific error conditions occur during USB CAN device operations, requiring system reboot to restore functionality.
If Mitigated
Minor system instability that may cause temporary disruption to CAN communications until system recovery.
🎯 Exploit Status
Exploitation requires triggering specific error conditions in the USB CAN driver, likely requiring physical access or control over USB devices. No known public exploits.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing fixes from the provided git commits
Vendor Advisory: https://git.kernel.org/stable/c/494fc029f662c331e06b7c2031deff3c64200eed
Restart Required: No
Instructions:
1. Update Linux kernel to version containing fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel package. 3. Rebuild kernel if using custom build. 4. No reboot required for kernel module reload, but recommended for stability.
🔧 Temporary Workarounds
Disable gs_usb module
allPrevent loading of vulnerable kernel module if CAN functionality not required
echo 'blacklist gs_usb' >> /etc/modprobe.d/blacklist.conf
rmmod gs_usb
🧯 If You Can't Patch
- Avoid using USB CAN devices with vulnerable systems
- Implement monitoring for kernel panic events and system crashes
🔍 How to Verify
Check if Vulnerable:
Check if gs_usb module is loaded: lsmod | grep gs_usb. Check kernel version against affected range.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits. Check dmesg for absence of related error messages during CAN operations.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in dmesg/syslog
- CAN driver error messages
- System crash reports
Network Indicators:
- Disruption in CAN bus communications
- USB device disconnection events
SIEM Query:
source="kernel" AND ("panic" OR "gs_usb" OR "CAN")🔗 References
- https://git.kernel.org/stable/c/494fc029f662c331e06b7c2031deff3c64200eed
- https://git.kernel.org/stable/c/713ba826ae114ab339c9a1b31e209bebdadb0ac9
- https://git.kernel.org/stable/c/8986cdf52f86208df9c7887fee23365b5d37da26
- https://git.kernel.org/stable/c/923379f1d7e3af8ccbf11edbbcf41f1bb3e9cfe6
- https://git.kernel.org/stable/c/aed58a28ea71a0d7d0947190fab1e3f4daa1d4a5
