CVE-2023-52602
📋 TL;DR
This CVE describes a slab-out-of-bounds read vulnerability in the JFS filesystem implementation within the Linux kernel. An attacker could exploit this to read kernel memory, potentially leading to information disclosure or system crashes. This affects all Linux systems using the JFS filesystem.
💻 Affected Systems
- Linux kernel with JFS filesystem support
📦 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 memory disclosure leading to privilege escalation or system crash/DoS
Likely Case
System crash or denial of service when accessing JFS filesystems
If Mitigated
Limited impact if JFS filesystem is not in use or proper access controls restrict user access
🎯 Exploit Status
Requires local access and ability to trigger the dtSearch function on JFS filesystems
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commits 1b9d6828589d57f94a23fb1c46112cda39d7efdb or later
Vendor Advisory: https://git.kernel.org/stable/c/1b9d6828589d57f94a23fb1c46112cda39d7efdb
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Reboot system. 3. Check kernel version to confirm update.
🔧 Temporary Workarounds
Disable JFS filesystem
linuxPrevent mounting or using JFS filesystems
# Unmount any JFS filesystems
umount /path/to/jfs/mount
# Blacklist JFS kernel module
echo 'blacklist jfs' >> /etc/modprobe.d/blacklist.conf
# Rebuild initramfs
update-initramfs -u
🧯 If You Can't Patch
- Restrict user access to systems with JFS filesystems mounted
- Implement strict access controls and monitoring on JFS filesystem operations
🔍 How to Verify
Check if Vulnerable:
Check if JFS filesystem is in use: 'mount | grep -i jfs' or 'lsmod | grep jfs'. If JFS is loaded/mounted and kernel is unpatched, system is vulnerable.Check Version:
uname -rVerify Fix Applied:
Check kernel version against distribution's security advisory and verify JFS module version.📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes when accessing files
- JFS-related error messages in dmesg
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for: 'kernel: BUG:', 'kernel: Oops:', 'jfs' in system logs🔗 References
- https://git.kernel.org/stable/c/1b9d6828589d57f94a23fb1c46112cda39d7efdb
- https://git.kernel.org/stable/c/1c40ca3d39d769931b28295b3145c25f1decf5a6
- https://git.kernel.org/stable/c/6c6a96c3d74df185ee344977d46944d6f33bb4dd
- https://git.kernel.org/stable/c/7110650b85dd2f1cee819acd1345a9013a1a62f7
- https://git.kernel.org/stable/c/bff9d4078a232c01e42e9377d005fb2f4d31a472
- https://git.kernel.org/stable/c/cab0c265ba182fd266c2aa3c69d7e40640a7f612
- https://git.kernel.org/stable/c/ce8bc22e948634a5c0a3fa58a179177d0e3f3950
- https://git.kernel.org/stable/c/fa5492ee89463a7590a1449358002ff7ef63529f
- https://git.kernel.org/stable/c/1b9d6828589d57f94a23fb1c46112cda39d7efdb
- https://git.kernel.org/stable/c/1c40ca3d39d769931b28295b3145c25f1decf5a6
- https://git.kernel.org/stable/c/6c6a96c3d74df185ee344977d46944d6f33bb4dd
- https://git.kernel.org/stable/c/7110650b85dd2f1cee819acd1345a9013a1a62f7
- https://git.kernel.org/stable/c/bff9d4078a232c01e42e9377d005fb2f4d31a472
- https://git.kernel.org/stable/c/cab0c265ba182fd266c2aa3c69d7e40640a7f612
- https://git.kernel.org/stable/c/ce8bc22e948634a5c0a3fa58a179177d0e3f3950
- https://git.kernel.org/stable/c/fa5492ee89463a7590a1449358002ff7ef63529f
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html
