CVE-2023-53363
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's PCI subsystem allows accessing freed memory during bus removal. This affects systems using PCI devices with the vulnerable kernel code, potentially leading to system crashes or kernel memory corruption. The issue occurs when pci_bus_release_domain_nr() accesses a freed pci_bus structure after pci_remove_bus() has already released it.
💻 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 panic, system crash, or potential privilege escalation if an attacker can manipulate the freed memory region to execute arbitrary code in kernel context.
Likely Case
System instability, kernel crashes, or denial of service when PCI devices are removed or during system shutdown/reboot sequences.
If Mitigated
Minor system instability during PCI operations if proper kernel protections are enabled, but no remote exploitation.
🎯 Exploit Status
Exploitation requires local access and ability to trigger PCI device removal. No public exploits known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in kernel commits: 07a75c0050e59c50f038cc5f4e2a3258c8f8c9d0, 30ba2d09edb5ea857a1473ae3d820911347ada62, 52b0343c7d628f37b38e3279ba585526b850ad3b, ad367516b1c09317111255ecfbf5e42c33e31918, fbf45385e3419b8698b5e0a434847072375cfec2
Vendor Advisory: https://git.kernel.org/stable/c/07a75c0050e59c50f038cc5f4e2a3258c8f8c9d0
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
Avoid PCI device hot removal
linuxPrevent triggering the vulnerable code path by avoiding PCI device removal operations
🧯 If You Can't Patch
- Restrict local user access to prevent potential exploitation
- Avoid hot-plugging or removing PCI devices while system is running
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with affected range. Vulnerable if kernel contains commit c14f7ccc9f5d but not the fix commits.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to include one of the fix commits. Check dmesg for no KFENCE use-after-free errors during PCI operations.📡 Detection & Monitoring
Log Indicators:
- KFENCE use-after-free errors in dmesg/kernel logs
- Kernel panic or oops messages related to pci_bus_release_domain_nr
SIEM Query:
source="kernel" AND ("pci_bus_release_domain_nr" OR "use-after-free" OR "KFENCE")🔗 References
- https://git.kernel.org/stable/c/07a75c0050e59c50f038cc5f4e2a3258c8f8c9d0
- https://git.kernel.org/stable/c/30ba2d09edb5ea857a1473ae3d820911347ada62
- https://git.kernel.org/stable/c/52b0343c7d628f37b38e3279ba585526b850ad3b
- https://git.kernel.org/stable/c/ad367516b1c09317111255ecfbf5e42c33e31918
- https://git.kernel.org/stable/c/fbf45385e3419b8698b5e0a434847072375cfec2
