CVE-2022-50363
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's skmsg subsystem where alloc_sk_msg() could be called from a non-sleepable context without proper gfp_t flags, potentially leading to memory corruption. This affects Linux systems with specific kernel configurations using skmsg functionality. Attackers could exploit this to cause kernel crashes or potentially execute arbitrary code.
💻 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, or potential privilege escalation to kernel-level code execution
Likely Case
System instability, kernel crashes, or denial of service
If Mitigated
Minimal impact with proper kernel hardening and isolation
🎯 Exploit Status
Exploitation requires specific conditions and kernel configuration. The vulnerability was discovered through fuzzing (syzbot).
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits 2d1f274b95c6e4ba6a813b3b8e7a1a38d54a0a08 and 693ddd6ffc05b228ea1638f9d757c5d3541f9446
Vendor Advisory: https://git.kernel.org/stable/c/2d1f274b95c6e4ba6a813b3b8e7a1a38d54a0a08
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check your distribution's security advisories for specific patched versions. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable skmsg functionality
LinuxDisable BPF and socket-related features that use skmsg if not required
echo 0 > /proc/sys/net/core/bpf_jit_enable
sysctl -w kernel.unprivileged_bpf_disabled=1
🧯 If You Can't Patch
- Implement strict network segmentation to limit exposure
- Apply kernel hardening measures and restrict unprivileged BPF operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if skmsg functionality is enabled. Vulnerable if using kernel before fix commits with skmsg features active.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits: 'uname -r' and check distribution patch notes📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- OOM killer activity
- System crash dumps
Network Indicators:
- Unusual socket behavior or connection failures
SIEM Query:
source="kernel" AND ("panic" OR "BUG" OR "slab" OR "skmsg")