Description
NILFS utilities through 2.3.0, fixed in commit 26efb5d, nilfs_sb_is_valid() function fails to validate s_log_block_size field in NILFS2 superblock before bit-shift operations. Attackers supplying crafted NILFS2 images trigger undefined behavior through oversized shifts or out-of-memory conditions, crashing tools like nilfs-tune and dumpseg.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| nilfs-dev | nilfs-utils | ≤ 2.3.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | nilfs-tools | No fix yet | — |
| Debian 13 | nilfs-tools | No fix yet | — |
| Debian 12 | nilfs-tools | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | nilfs-tools | No fix yet | — |
| Ubuntu 26.04 LTS | nilfs-tools | No fix yet | — |
| Ubuntu 25.10 | nilfs-tools | No fix yet | — |
| Ubuntu 24.04 LTS | nilfs-tools | No fix yet | — |
| Ubuntu 22.04 LTS | nilfs-tools | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | nilfs-tools | No fix yet | — |
| Ubuntu 18.04 LTS | nilfs-tools | No fix yet | — |
| Ubuntu 16.04 LTS | nilfs-tools | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | nilfs-utils | 2.3.1-1.1 | openSUSE-SU-2026:11094-1 |
| openSUSE Leap 16.0 | nilfs-utils | 2.2.9-bp160.2.1 | openSUSE-SU-2026:21183-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | nilfs-utils | No fix yet | — |
Advisories 2
- openSUSE-SU-2026:21183-1 Security update for nilfs-utils SUSE / openSUSE Security Updates · Jul 2, 2026
- openSUSE-SU-2026:11094-1 libnilfs3-2.3.1-1.1 on GA media SUSE / openSUSE Security Updates · Jun 24, 2026
References
- Pull Request issue-tracking
- Patch Commit patch