CVE-2024-49888
📋 TL;DR
This CVE addresses a signed division overflow vulnerability in the Linux kernel's BPF subsystem. When a BPF program performs specific signed division operations (LLONG_MIN/-1 or INT_MIN/-1), it can trigger a kernel crash on x86_64 systems or produce incorrect results on ARM64 systems. This affects systems running vulnerable Linux kernel versions with BPF enabled.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially disrupting critical services.
Likely Case
System crash or instability when malicious or buggy BPF programs trigger the division edge case.
If Mitigated
No impact if patched or if BPF is disabled/unavailable to unprivileged users.
🎯 Exploit Status
Exploitation requires local access with BPF privileges. No known public exploits at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 4902a6a0dc59, 7dd34d7b7dcf, or d22e45a369af
Vendor Advisory: https://git.kernel.org/stable/c/4902a6a0dc593c82055fc8c9ada371bafe26c9cc
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify kernel version matches patched release.
🔧 Temporary Workarounds
Disable unprivileged BPF
linuxPrevent unprivileged users from loading BPF programs
sysctl -w kernel.unprivileged_bpf_disabled=1
echo 'kernel.unprivileged_bpf_disabled=1' >> /etc/sysctl.conf
sysctl -p
Restrict BPF capabilities
linuxUse Linux capabilities to limit who can load BPF programs
setcap -r /path/to/program
Use namespaces/cgroups to isolate BPF usage
🧯 If You Can't Patch
- Implement strict BPF program auditing and monitoring
- Isolate systems with vulnerable kernels from untrusted users
🔍 How to Verify
Check if Vulnerable:
Check kernel version against distribution security advisories. Run: uname -r and compare with patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits or is newer than vulnerable versions. Check distribution security updates.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- 'divide error' in kernel logs
- BPF program loading failures
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("divide error" OR "Oops" OR "BPF")