CVE-2023-53026
📋 TL;DR
A Linux kernel vulnerability in the RDMA subsystem allows an integer overflow when registering DMA memory regions with specific alignment conditions. This can cause an infinite loop in the kernel, leading to denial of service. Systems using RDMA functionality with certain memory configurations are affected.
💻 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 or system hang due to infinite loop in kernel space, requiring hard reboot and causing extended downtime.
Likely Case
Local denial of service where a privileged user or process triggers the infinite loop, freezing the system or specific RDMA operations.
If Mitigated
Minimal impact if RDMA is disabled or systems don't use the specific memory alignment patterns that trigger the overflow.
🎯 Exploit Status
Requires local access and ability to trigger RDMA memory registration with specific parameters. The backtrace shows it occurs during efa_register_mr operations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits: 0afec5e9cea732cb47014655685a2a47fb180c31, 362c9489720b31b6aa7491423ba65a4e98aa9838, 43811d07ea64366af8ec9e168c558ec51440c39e, 902063a9fea5f8252df392ade746bc9cfd07a5ae, d66c1d4178c219b6e7d7a6f714e3e3656faccc36
Vendor Advisory: https://git.kernel.org/stable/c/0afec5e9cea732cb47014655685a2a47fb180c31
Restart Required: Yes
Instructions:
1. Update to a kernel version containing the fix commits. 2. Check your distribution's security advisories for backported patches. 3. Reboot the system after kernel update.
🔧 Temporary Workarounds
Disable RDMA functionality
linuxPrevent exploitation by disabling RDMA if not required
modprobe -r rdma_cm
modprobe -r ib_core
echo 'blacklist rdma_cm' >> /etc/modprobe.d/blacklist.conf
echo 'blacklist ib_core' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Restrict RDMA access to trusted users and processes only
- Monitor system logs for RDMA-related errors or hangs
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if RDMA modules are loaded: 'uname -r' and 'lsmod | grep -E "(rdma|ib_)"'Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits: 'uname -r' and check with distribution's patch tracking📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing 'efa_reg_user_mr_dmabuf' or 'efa_register_mr' with large memory sizes
- System hangs or high CPU usage in kernel threads
- RDMA-related error messages in dmesg
Network Indicators:
- Unusual RDMA traffic patterns if network RDMA is used
SIEM Query:
source="kernel" AND ("efa_reg_user_mr_dmabuf" OR "efa_register_mr" OR "RDMA" AND "hang" OR "loop")🔗 References
- https://git.kernel.org/stable/c/0afec5e9cea732cb47014655685a2a47fb180c31
- https://git.kernel.org/stable/c/362c9489720b31b6aa7491423ba65a4e98aa9838
- https://git.kernel.org/stable/c/43811d07ea64366af8ec9e168c558ec51440c39e
- https://git.kernel.org/stable/c/902063a9fea5f8252df392ade746bc9cfd07a5ae
- https://git.kernel.org/stable/c/d66c1d4178c219b6e7d7a6f714e3e3656faccc36
