CVE-2025-37803
📋 TL;DR
A buffer size overflow vulnerability in the Linux kernel's udmabuf driver allows local attackers to cause memory corruption during udmabuf creation. This affects Linux systems with the udmabuf driver enabled, potentially leading to privilege escalation or denial of service. The vulnerability stems from improper casting of size_limit_mb to u64 when calculating page limits.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation to root, kernel panic causing system crash, or arbitrary code execution in kernel context.
Likely Case
Kernel crash leading to denial of service, system instability, or memory corruption affecting system reliability.
If Mitigated
Limited impact if proper access controls restrict local user access and kernel hardening features are enabled.
🎯 Exploit Status
Requires local access and ability to trigger udmabuf creation. Exploit would need to bypass kernel protections like KASLR and SMAP/SMEP.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel trees (commits provided in references)
Vendor Advisory: https://git.kernel.org/stable/c/021ba7f1babd029e714d13a6bf2571b08af96d0f
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from distribution vendor. 2. Rebuild kernel if using custom kernel with patches from git.kernel.org. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable udmabuf module
linuxPrevent loading of vulnerable udmabuf kernel module
echo 'blacklist udmabuf' >> /etc/modprobe.d/blacklist-udmabuf.conf
rmmod udmabuf
Restrict local user access
linuxLimit which users can create udmabuf devices
chmod 600 /dev/udmabuf*
setfacl -m u:root:rw /dev/udmabuf*
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges
- Monitor system logs for udmabuf-related errors or crashes
🔍 How to Verify
Check if Vulnerable:
Check if udmabuf module is loaded: lsmod | grep udmabuf. Check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and udmabuf module version matches patched commit hashes.📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes or panics
- udmabuf-related errors in dmesg
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("udmabuf" OR "buffer overflow" OR "kernel panic")🔗 References
- https://git.kernel.org/stable/c/021ba7f1babd029e714d13a6bf2571b08af96d0f
- https://git.kernel.org/stable/c/13fe12c037b470321436deec393030c6153cfeb9
- https://git.kernel.org/stable/c/29b65a3171a49c9b69f31035146be966cec40b7a
- https://git.kernel.org/stable/c/2b8419c6ecf69007dcff54ea0b9f0b215282c55a
- https://git.kernel.org/stable/c/373512760e13fdaa726faa9502d0f5be2abb3d33
- https://git.kernel.org/stable/c/3f6c9d66e0f8eb9679b57913aa64b4d2266f6fbe
- https://git.kernel.org/stable/c/b2ff4e9c599b000833d16a917f519aa2e4a75de2
- https://git.kernel.org/stable/c/e84a08fc7e25cdad5d9a3def42cc770ff711193f
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
