CVE-2022-50864
Shift-Out-of-Bounds Vulnerability in Linux nilfs2 Causes Kernel Panic
Publication date: 2025-12-30
Last updated on: 2025-12-30
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | kernel | * |
| linux | nilfs2 | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability be detected on my network or system? Can you suggest some commands?
You can detect this vulnerability by checking for kernel panic logs or warnings related to 'shift exponent' errors in the system logs. Specifically, look for messages like 'shift exponent ... is too large for 32-bit type int' in kernel logs (e.g., using dmesg or journalctl). Commands to check include: 'dmesg | grep shift exponent' or 'journalctl -k | grep shift exponent'.
Can you explain this vulnerability to me?
This vulnerability occurs in the Linux kernel's nilfs2 file system where a corrupted superblock field (s_log_block_size) with an excessively large exponent can cause a shift-out-of-bounds error. This leads to a warning and potentially a kernel panic if the system is configured to panic on warnings. The issue arises because the exponent value is too large for a 32-bit integer type, causing unsafe operations during nilfs2 initialization and mounting.
How can this vulnerability impact me? :
If exploited or triggered, this vulnerability can cause the Linux kernel to panic, leading to a system crash or denial of service. This can disrupt system availability and stability, potentially causing downtime or data access interruptions.
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation involves updating the Linux kernel to a version where the nilfs2 shift-out-of-bounds issue is fixed. This fix includes a new helper function that performs sanity checks on block size exponents to prevent kernel panic. Until the update is applied, avoid mounting corrupted nilfs2 filesystems that could trigger this issue.