CVE-2022-49276
📋 TL;DR
This CVE describes a memory leak vulnerability in the Linux kernel's JFFS2 filesystem driver. When mounting a JFFS2 filesystem fails during scanning, allocated memory isn't properly freed, leading to kernel memory exhaustion over time. This affects any Linux system using JFFS2 filesystems.
💻 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
Repeated exploitation could exhaust kernel memory, causing system instability, crashes, or denial of service through kernel panic.
Likely Case
System instability or crashes when mounting corrupted JFFS2 filesystems, particularly during boot or filesystem operations.
If Mitigated
Minimal impact with proper monitoring and memory limits, though potential for gradual memory degradation.
🎯 Exploit Status
Requires ability to mount JFFS2 filesystems and trigger error conditions in jffs2_scan_eraseblock().
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in stable kernel versions via commits referenced in CVE
Vendor Advisory: https://git.kernel.org/stable/c/9b0c69182f09b70779817af4dcf89780955d5c4c
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. For custom kernels, apply commits from kernel.org. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable JFFS2 module
linuxPrevent loading of JFFS2 filesystem driver if not needed
echo 'blacklist jffs2' >> /etc/modprobe.d/blacklist.conf
rmmod jffs2
Restrict filesystem mounting
linuxLimit which users can mount filesystems
Edit /etc/fstab with 'noauto' for JFFS2 partitions
Use mount permissions in /etc/fstab
🧯 If You Can't Patch
- Avoid using JFFS2 filesystems where possible
- Implement kernel memory monitoring and alerts for unusual consumption
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if JFFS2 module is loaded: lsmod | grep jffs2 && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is after fix commits and test mounting JFFS2 filesystems while monitoring memory📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- Out of memory errors in dmesg
- JFFS2 mount failures in system logs
Network Indicators:
- None - local filesystem vulnerability
SIEM Query:
source="kernel" AND ("jffs2" OR "out of memory" OR "kernel panic")🔗 References
- https://git.kernel.org/stable/c/455f4a23490bfcbedc8e5c245c463a59b19e5ddd
- https://git.kernel.org/stable/c/51dbb5e36d59f62e34d462b801c1068248149cfe
- https://git.kernel.org/stable/c/52ba0ab4f0a606f02a6163493378989faa1ec10a
- https://git.kernel.org/stable/c/82462324bf35b6b553400af1c1aa265069cee28f
- https://git.kernel.org/stable/c/9b0c69182f09b70779817af4dcf89780955d5c4c
- https://git.kernel.org/stable/c/9cdd3128874f5fe759e2c4e1360ab7fb96a8d1df
- https://git.kernel.org/stable/c/b26bbc0c122cad038831f226a4cb4de702225e16
- https://git.kernel.org/stable/c/b36bccb04e14cc0c1e2d0e92d477fe220314fad6
- https://git.kernel.org/stable/c/e711913463af916d777a4873068f415f1fe2ad33
