CVE-2025-38197
📋 TL;DR
A NULL pointer dereference vulnerability in the Linux kernel's dell_rbu driver allows local attackers to cause denial of service or potentially escalate privileges. The bug occurs when the driver incorrectly handles list operations while reading packet data via sysfs. This affects Linux systems with the dell_rbu module loaded, typically Dell hardware users.
💻 Affected Systems
- Linux kernel with dell_rbu driver
📦 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, with potential for privilege escalation if combined with other vulnerabilities.
Likely Case
System crash or instability when accessing dell_rbu sysfs interfaces, causing denial of service on affected Dell systems.
If Mitigated
Minimal impact if dell_rbu module is not loaded or sysfs access is restricted to privileged users only.
🎯 Exploit Status
Requires local access and ability to interact with sysfs. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commits 07d7b8e7ef7d1f812a6211ed531947c56d09e95e or later
Vendor Advisory: https://git.kernel.org/stable/c/07d7b8e7ef7d1f812a6211ed531947c56d09e95e
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify dell_rbu module is not loaded if not needed.
🔧 Temporary Workarounds
Unload dell_rbu module
linuxRemove the vulnerable kernel module if not required
sudo rmmod dell_rbu
Blacklist dell_rbu module
linuxPrevent module from loading at boot
echo 'blacklist dell_rbu' | sudo tee /etc/modprobe.d/blacklist-dell_rbu.conf
🧯 If You Can't Patch
- Restrict access to /sys/class/firmware/dell_rbu/ to root only
- Monitor system logs for kernel panic or NULL pointer dereference events
🔍 How to Verify
Check if Vulnerable:
Check if dell_rbu module is loaded: lsmod | grep dell_rbuCheck Version:
uname -rVerify Fix Applied:
Check kernel version is patched and dell_rbu module version matches fixed kernel📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference in kernel logs
- Oops messages mentioning dell_rbu
Network Indicators:
- None - local vulnerability only
SIEM Query:
event_source="kernel" AND (message CONTAINS "dell_rbu" OR message CONTAINS "NULL pointer dereference")🔗 References
- https://git.kernel.org/stable/c/07d7b8e7ef7d1f812a6211ed531947c56d09e95e
- https://git.kernel.org/stable/c/32d05e6cc3a7bf6c8f16f7b7ef8fe80eca0c233e
- https://git.kernel.org/stable/c/4d71f2c1e5263a9f042faa71d59515709869dc79
- https://git.kernel.org/stable/c/5e8c658acd1b7c186aeffa46bf08795e121f401a
- https://git.kernel.org/stable/c/61ce04601e0d8265ec6d2ffa6df5a7e1bce64854
- https://git.kernel.org/stable/c/a7b477b64ef5e37cb08dd536ae07c46f9f28262e
- https://git.kernel.org/stable/c/f3b840fb1508a80cd8a0efb5c886ae1995a88b24
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
