CVE-2023-53326
📋 TL;DR
A NULL pointer dereference vulnerability in the Linux kernel's powerpc architecture allows kernel crashes when generating core dumps for PF_IO_WORKER tasks with NULL pt_regs. This affects Linux systems running on PowerPC architecture. The vulnerability can cause denial of service through kernel panics.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially requiring physical access or remote management to reboot.
Likely Case
System crash when specific IO worker tasks trigger core dump generation, causing temporary service disruption.
If Mitigated
Minimal impact if systems don't use PF_IO_WORKER tasks or have core dumps disabled for these tasks.
🎯 Exploit Status
Requires ability to create PF_IO_WORKER tasks and trigger core dumps. Not trivial to exploit remotely.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 01849382373b, 064a1c7b0f84, 7624973bc15b, 80a4200d51e5, fd7276189450
Vendor Advisory: https://git.kernel.org/stable/c/01849382373b867ddcbe7536b9dfa89f3bcea60e
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable core dumps for IO worker tasks
LinuxPrevent core dump generation for PF_IO_WORKER tasks to avoid triggering the vulnerability
ulimit -c 0
sysctl -w kernel.core_pattern="|/bin/false"
🧯 If You Can't Patch
- Restrict creation of PF_IO_WORKER tasks to trusted users only
- Monitor for kernel panic events and implement rapid recovery procedures
🔍 How to Verify
Check if Vulnerable:
Check kernel version and architecture: uname -r and uname -m. If PowerPC and kernel version before fixes, system is vulnerable.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or is from distribution that has backported the patches.📡 Detection & Monitoring
Log Indicators:
- Kernel NULL pointer dereference messages
- Oops: Kernel access of bad area
- Kernel panic logs related to ppr_get or memcpy_power7
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "Oops: Kernel access of bad area" OR "ppr_get" OR "memcpy_power7")🔗 References
- https://git.kernel.org/stable/c/01849382373b867ddcbe7536b9dfa89f3bcea60e
- https://git.kernel.org/stable/c/064a1c7b0f8403260d77627e62424a72ca26cee2
- https://git.kernel.org/stable/c/7624973bc15b76d000e8e6f9b8080fcb76d36595
- https://git.kernel.org/stable/c/80a4200d51e5a7e046f4a90f5faa5bafd5a60c58
- https://git.kernel.org/stable/c/fd7276189450110ed835eb0a334e62d2f1c4e3be
