CVE-2025-37915
📋 TL;DR
A double-free vulnerability in the Linux kernel's DRR (Deficit Round Robin) qdisc scheduler occurs when netem is used as a child qdisc, causing reentrant enqueue operations. This leads to memory corruption by adding the same classifier to a list twice. Systems running affected Linux kernel versions with specific qdisc configurations are vulnerable.
💻 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 →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 →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, system crash, or potential privilege escalation leading to full system compromise.
Likely Case
System instability, kernel crashes, or denial of service affecting network performance.
If Mitigated
Minimal impact if proper network segmentation and kernel hardening are implemented.
🎯 Exploit Status
Exploitation requires local access or ability to manipulate network qdisc configurations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check kernel commits: 26e75716b94d6ff9be5ea07d63675c4d189f30b4, 2968632880f1792007eedd12eeedf7f6e2b7e9f3, 4b07ac06b0a712923255aaf2691637693fc7100d, 4f0ecf50cdf76da95828578a92f130b653ac2fcf, 5da3aad1a13e7edb8ff0778a444ccf49930313e9
Vendor Advisory: https://git.kernel.org/stable/c/26e75716b94d6ff9be5ea07d63675c4d189f30b4
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Reboot system. 3. Verify kernel version matches patched commit.
🔧 Temporary Workarounds
Disable vulnerable qdisc configurations
linuxAvoid using DRR qdisc with netem as child qdisc.
tc qdisc del dev <interface> root
tc qdisc add dev <interface> root <alternative_qdisc>
🧯 If You Can't Patch
- Avoid using DRR qdisc with netem child configurations.
- Implement network segmentation to limit potential impact.
🔍 How to Verify
Check if Vulnerable:
Check kernel version and qdisc configuration: 'uname -r' and 'tc qdisc show'.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes patched commits and test qdisc functionality.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- System crash dumps
- Network performance anomalies
Network Indicators:
- Unusual network latency or packet loss patterns
SIEM Query:
search 'kernel panic' OR 'system crash' AND 'qdisc' OR 'netem'🔗 References
- https://git.kernel.org/stable/c/26e75716b94d6ff9be5ea07d63675c4d189f30b4
- https://git.kernel.org/stable/c/2968632880f1792007eedd12eeedf7f6e2b7e9f3
- https://git.kernel.org/stable/c/4b07ac06b0a712923255aaf2691637693fc7100d
- https://git.kernel.org/stable/c/4f0ecf50cdf76da95828578a92f130b653ac2fcf
- https://git.kernel.org/stable/c/5da3aad1a13e7edb8ff0778a444ccf49930313e9
- https://git.kernel.org/stable/c/ab2248110738d4429668140ad22f530a9ee730e1
- https://git.kernel.org/stable/c/db205b92dfe0501e5b92fb7cf00971d0e44ba3eb
- https://git.kernel.org/stable/c/f99a3fbf023e20b626be4b0f042463d598050c9a
- https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
