CVE-2025-38179
📋 TL;DR
A buffer overflow vulnerability in the Linux kernel's SMB client allows attackers to write beyond allocated memory boundaries when processing RDMA operations. This affects systems using CIFS/SMB file sharing with RDMA enabled. The vulnerability can lead to kernel crashes or potential privilege escalation.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash or potential arbitrary code execution with kernel privileges, enabling full system compromise.
Likely Case
System instability, kernel crashes (denial of service), or memory corruption leading to unpredictable behavior.
If Mitigated
Limited impact if RDMA is disabled or systems are isolated from untrusted SMB servers.
🎯 Exploit Status
Requires ability to trigger SMB operations with specific RDMA configurations. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 8ae7814589d7bd850294ac14ec4c1725dafd42ca, a379a8a2a0032e12e7ef397197c9c2ad011588d6, or e0ba9b2f188166550296005e64b15e80db82ad8a
Vendor Advisory: https://git.kernel.org/stable/c/8ae7814589d7bd850294ac14ec4c1725dafd42ca
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable RDMA for CIFS/SMB
linuxPrevent use of RDMA in SMB client to avoid triggering vulnerable code path
echo 'options cifs rdma=0' > /etc/modprobe.d/cifs-rdma-disable.conf
rmmod cifs
modprobe cifs
🧯 If You Can't Patch
- Disable RDMA support in CIFS/SMB client configuration
- Restrict SMB access to trusted servers only
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if CIFS module with RDMA support is loaded: 'lsmod | grep cifs' and check for RDMA featuresCheck Version:
uname -rVerify Fix Applied:
Verify kernel version contains fix commits or is newer than vulnerable versions. Check 'uname -r' and compare with patched versions from vendor.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- KASAN reports for slab-out-of-bounds in smb_set_sge
- System crashes during SMB operations
Network Indicators:
- Unusual SMB traffic patterns triggering RDMA operations
SIEM Query:
kernel: "BUG: KASAN: slab-out-of-bounds in smb_set_sge" OR kernel: "panic" AND process:"cifs"