Kernel panic via inconsistent valid-block accounting
Published Jul 3, 2025 · Updated May 11, 2026
Denial of service in Linux kernel F2FS allows local users to panic the kernel by truncating a file on a crafted filesystem image. The dec_valid_block_count routine trusts that inode-mapped blocks do not exceed sbi->total_valid_block_count and invokes BUG_ON when malformed metadata violates that invariant. Reachability requires a crafted F2FS image to be mounted and a file on it truncated; the documented consequence is a kernel panic and host service interruption.
Summary
What happened
Denial of service in Linux kernel F2FS allows local users to panic the kernel by truncating a file on a crafted filesystem image. The dec_valid_block_count routine trusts that inode-mapped blocks do not exceed sbi->total_valid_block_count and invokes BUG_ON when malformed metadata violates that invariant. Reachability requires a crafted F2FS image to be mounted and a file on it truncated; the documented consequence is a kernel panic and host service interruption.
The record
- CVE
- CVE-2025-38163
- Published
- Jul 3, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 3, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=3.8
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <05872a167c2cab80ef186ef23cc34a6776a1a30c
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <25f3776b58c1c45ad2e50ab4b263505b4d2378ca
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <49bc7bf38e42cfa642787e947f5721696ea73ac3
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <65b3f76592aed5a43c4d79375ac097acf975972b
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <6a324d77f7ea1a91d55c4b6ad970e3ac9ab6a20d
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <a39cc43efc1bca74ed9d6cf9e60b995071f7d178
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <ccc28c0397f75a3ec9539cceed9db014d7b73869
- Affected versionversion=39a53e0ce0df01b3cf4bb898c7ae2fd2189647d5 <f1b743c1955151bd392539b739a3ad155296be13
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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