CVE-2024-40927
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's xHCI driver allows attackers to cause system crashes or potentially execute arbitrary code. This affects Linux systems using USB 3.x devices with multiple streams, particularly when handling read errors on storage devices. The vulnerability can lead to kernel panics, IOMMU faults, or memory corruption.
💻 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
Kernel crash leading to denial of service, potential arbitrary code execution in kernel context, or system instability requiring reboot.
Likely Case
System crashes or hangs when USB devices encounter errors, particularly with UAS storage devices during read failures.
If Mitigated
Reduced risk of crashes but potential performance impact on USB operations.
🎯 Exploit Status
Exploitation requires triggering specific USB error conditions with multiple streams. Reproducible with hdparm marking bad sectors and reading devices in loop.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 26460c1afa31, 5ceac4402f5d, 61593dc413c3, 633f72cb6124, or 949be4ec5835
Vendor Advisory: https://git.kernel.org/stable/c/26460c1afa311524f588e288a4941432f0de6228
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Check kernel version with 'uname -r'. 3. Reboot system after update. 4. Verify fix with 'dmesg | grep -i xhci' for absence of related warnings.
🔧 Temporary Workarounds
Disable USB 3.x multiple streams
linuxPrevent use of multiple streams feature in xHCI driver
echo 0 > /sys/module/xhci_hcd/parameters/streams
Avoid UAS devices
linuxUse USB storage in BOT mode instead of UAS
modprobe -r uas
modprobe usb-storage quirks=0xXXXX:0xXXXX:u
🧯 If You Can't Patch
- Monitor system logs for xhci_warn messages and USB-related crashes
- Restrict USB device access to trusted users only
🔍 How to Verify
Check if Vulnerable:
Check kernel version with 'uname -r' and compare with affected versions. Monitor 'dmesg | grep -i xhci' for warnings about multiple streams.Check Version:
uname -rVerify Fix Applied:
After patching, verify kernel version and check that USB operations with error conditions don't cause crashes. Run 'dmesg | grep -i "xhci.*stream"' for absence of warnings.📡 Detection & Monitoring
Log Indicators:
- xhci_warn messages about multiple streams
- Kernel panic/Oops related to xhci
- IOMMU fault errors
- USB device disconnection errors
Network Indicators:
- N/A - local vulnerability
SIEM Query:
source="kernel" AND ("xhci" OR "USB") AND ("panic" OR "Oops" OR "warning")🔗 References
- https://git.kernel.org/stable/c/26460c1afa311524f588e288a4941432f0de6228
- https://git.kernel.org/stable/c/5ceac4402f5d975e5a01c806438eb4e554771577
- https://git.kernel.org/stable/c/61593dc413c3655e4328a351555235bc3089486a
- https://git.kernel.org/stable/c/633f72cb6124ecda97b641fbc119340bd88d51a9
- https://git.kernel.org/stable/c/949be4ec5835e0ccb3e2a8ab0e46179cb5512518
- https://git.kernel.org/stable/c/26460c1afa311524f588e288a4941432f0de6228
- https://git.kernel.org/stable/c/5ceac4402f5d975e5a01c806438eb4e554771577
- https://git.kernel.org/stable/c/61593dc413c3655e4328a351555235bc3089486a
- https://git.kernel.org/stable/c/633f72cb6124ecda97b641fbc119340bd88d51a9
- https://git.kernel.org/stable/c/949be4ec5835e0ccb3e2a8ab0e46179cb5512518
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
