CVE-2026-23373 Overview
A vulnerability has been resolved in the Linux kernel's WiFi RSI driver. The issue occurs in the rsi_mac80211_config function where the default return value of -EOPNOTSUPP triggers a WARN_ON in ieee80211_hw_conf_init. This behavior deviates from the expected driver implementation, as other drivers default to returning 0 for successful operation.
Critical Impact
This vulnerability affects Linux kernel WiFi subsystem stability, potentially causing unexpected warnings during wireless hardware configuration initialization that could impact system reliability.
Affected Products
- Linux kernel with RSI WiFi driver enabled
- Systems using Redpine Signals WiFi chipsets
- Linux distributions with affected kernel versions
Discovery Timeline
- 2026-03-25 - CVE CVE-2026-23373 published to NVD
- 2026-03-25 - Last updated in NVD database
Technical Details for CVE-2026-23373
Vulnerability Analysis
The vulnerability resides in the RSI (Redpine Signals Inc.) WiFi driver's mac80211 configuration function within the Linux kernel. When the rsi_mac80211_config function is called, it incorrectly defaults to returning -EOPNOTSUPP (Operation Not Supported) even in cases where no specific configuration error occurs. This return value propagates to the ieee80211_hw_conf_init function in the kernel's WiFi subsystem, which interprets this as an unexpected failure condition and triggers a WARN_ON macro. This warning mechanism is designed to alert developers and administrators to abnormal kernel behavior, but in this case, it creates false positives during normal driver initialization.
Root Cause
The root cause stems from improper default return value handling in the rsi_mac80211_config function. The function was designed to return -EOPNOTSUPP as a fallback, but this contradicts the expected behavior of mac80211 configuration callbacks. Other WiFi drivers in the Linux kernel correctly default to returning 0 (success) when no error condition exists, which is the semantically correct approach for configuration functions that may not need to perform any action.
Attack Vector
This is a software defect rather than a traditionally exploitable security vulnerability. The attack vector is local and requires no special privileges beyond normal system access with WiFi hardware present. The impact is limited to triggering kernel warnings and potentially causing system instability in environments with strict kernel warning policies. The vulnerability cannot be remotely exploited and does not provide privilege escalation capabilities.
The fix modifies the default return value in rsi_mac80211_config from -EOPNOTSUPP to 0, aligning the RSI driver's behavior with other WiFi drivers and eliminating the spurious WARN_ON triggers.
Detection Methods for CVE-2026-23373
Indicators of Compromise
- Presence of WARN_ON messages in kernel logs (dmesg) related to ieee80211_hw_conf_init
- WiFi driver initialization warnings specifically referencing the RSI driver module
- System stability issues during wireless network configuration on systems with Redpine Signals chipsets
Detection Strategies
- Monitor system logs for kernel warnings containing ieee80211_hw_conf_init or rsi_mac80211_config function references
- Review dmesg output after WiFi driver loading for any WARN_ON stack traces
- Implement kernel log parsing to detect anomalous WiFi subsystem warnings
Monitoring Recommendations
- Configure centralized log collection to capture kernel warnings across affected systems
- Set up alerts for repeated kernel warnings in the WiFi subsystem stack
- Monitor system uptime metrics for unexpected reboots that may be related to kernel warning policies
How to Mitigate CVE-2026-23373
Immediate Actions Required
- Apply the available kernel patches from the Linux kernel stable tree
- Update to a kernel version containing the fix for the RSI driver
- Consider disabling the RSI driver module if not required until patching is complete
Patch Information
Multiple kernel patches are available addressing this vulnerability:
- Kernel Patch - Commit 67d10e8d
- Kernel Patch - Commit 95ed0764
- Kernel Patch - Commit b64fbd71
- Kernel Patch - Commit d973b103
The patches modify the default return behavior in rsi_mac80211_config to return 0 instead of -EOPNOTSUPP, consistent with other WiFi driver implementations.
Workarounds
- Temporarily blacklist the rsi_91x kernel module if RSI WiFi hardware is not in use
- Configure kernel boot parameters to suppress WARN_ON panics if applicable to your environment
- Use alternative WiFi hardware or drivers until the kernel can be updated
# Temporarily disable RSI WiFi driver module
echo "blacklist rsi_91x" | sudo tee /etc/modprobe.d/disable-rsi.conf
sudo update-initramfs -u
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
