System crash via corrupted NILFS2 metadata inode
Published Oct 20, 2022 · Updated Apr 15, 2025
Null pointer dereference in Linux kernel NILFS2 allows local users to crash the system by mounting a crafted filesystem image. A corrupted i_mode value in a metadata-file inode causes nilfs_read_inode_common to skip bmap initialization, leaving nilfs_bmap_lookup_at_level to dereference a null pointer. Access to mount the crafted NILFS2 image is required, and successful triggering crashes the kernel rather than exposing or modifying data.
Summary
What happened
Null pointer dereference in Linux kernel NILFS2 allows local users to crash the system by mounting a crafted filesystem image. A corrupted i_mode value in a metadata-file inode causes nilfs_read_inode_common to skip bmap initialization, leaving nilfs_bmap_lookup_at_level to dereference a null pointer. Access to mount the crafted NILFS2 image is required, and successful triggering crashes the kernel rather than exposing or modifying data.
The record
- CVE
- CVE-2022-3621
- Published
- Oct 20, 2022
- Updated
- Apr 15, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-404, CWE-476, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 20, 2022CVE publishedPublication date reported by the CVE source.
- Apr 15, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=n/a
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- syzbot NILFS2 crash reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo