CVE-2023-53210
📋 TL;DR
A race condition in the Linux kernel's RAID5 cache subsystem can cause a null pointer dereference, leading to kernel panic and system crash. This affects Linux systems using software RAID5 with write-back caching enabled. The vulnerability requires local access to trigger.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Complete system crash and denial of service, requiring physical or remote console access to reboot.
Likely Case
System crash and denial of service affecting RAID5 arrays with write-back caching.
If Mitigated
Minimal impact if systems are patched or don't use RAID5 write-back caching.
🎯 Exploit Status
Requires local access and ability to trigger the race condition in RAID5 cache operations. Timing-dependent exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 0d0bd28c500173bfca78aa840f8f36d261ef1765, 711fb92606208a8626b785da4f9f23d648a5b6c8, 7a8b6d93991bf4b72b3f959baea35397c6c8e521, e46b2e7be8059d156af8c011dd8d665229b65886
Vendor Advisory: https://git.kernel.org/stable/c/0d0bd28c500173bfca78aa840f8f36d261ef1765
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable RAID5 write-back caching
linuxDisable the r5l write-back cache for RAID5 arrays to prevent triggering the vulnerability
echo 'write-behind' > /sys/block/mdX/md/stripe_cache_size
echo '0' > /sys/block/mdX/md/stripe_cache_size
🧯 If You Can't Patch
- Disable RAID5 write-back caching on all affected arrays
- Monitor system logs for kernel panic events and have reboot procedures ready
🔍 How to Verify
Check if Vulnerable:
Check if system uses software RAID5 with write-back caching: cat /proc/mdstat and check /sys/block/md*/md/stripe_cache_sizeCheck Version:
uname -rVerify Fix Applied:
Check kernel version contains one of the fix commits: uname -r and verify with distribution patch notes📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/messages or dmesg
- NULL pointer dereference errors mentioning r5l_flush_stripe_to_raid or r5l_log_flush_endio
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("panic" OR "NULL pointer dereference" OR "r5l_flush_stripe_to_raid" OR "r5l_log_flush_endio")