# CVE-2025-37925: jfs: reject on-disk inodes of an unsupported type

> A local attacker can cause a kernel crash by mounting a crafted JFS filesystem with unsupported inode types, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Apr 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-37925, DEBIAN-CVE-2025-37925, GHSA-8ccv-3j8r-hx7f, ROOT-OS-DEBIAN-11-CVE-2025-37925, ROOT-OS-DEBIAN-12-CVE-2025-37925, ROOT-OS-UBUNTU-2204-CVE-2025-37925, ROOT-OS-UBUNTU-2404-CVE-2025-37925, UBUNTU-CVE-2025-37925

## What is CVE-2025-37925?

CVE-2025-37925 is a medium-severity vulnerability in Linux kernel, published on 18 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

jfs: reject on-disk inodes of an unsupported type

Syzbot has reported the following BUG:

kernel BUG at fs/inode.c:668!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 3 UID: 0 PID: 139 Comm: jfsCommit Not tainted 6.12.0-rc4-syzkaller-00085-g4e46774408d9 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
RIP: 0010:clear_inode+0x168/0x190
Code: 4c 89 f7 e8 ba fe e5 ff e9 61 ff ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 7c c1 4c 89 f7 e8 90 ff e5 ff eb b7
 0b e8 01 5d 7f ff 90 0f 0b e8 f9 5c 7f ff 90 0f 0b e8 f1 5c 7f
RSP: 0018:ffffc900027dfae8 EFLAGS: 00010093
RAX: ffffffff82157a87 RBX: 0000000000000001 RCX: ffff888104d4b980
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900027dfc90 R08: ffffffff82157977 R09: fffff520004fbf38
R10: dffffc0000000000 R11: fffff520004fbf38 R12: dffffc0000000000
R13: ffff88811315bc00 R14: ffff88811315bda8 R15: ffff88811315bb80
FS:  0000000000000000(0000) GS:ffff888135f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005565222e0578 CR3: 0000000026ef0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 ? __die_body+0x5f/0xb0
 ? die+0x9e/0xc0
 ? do_trap+0x15a/0x3a0
 ? clear_inode+0x168/0x190
 ? do_error_trap+0x1dc/0x2c0
 ? clear_inode+0x168/0x190
 ? __pfx_do_error_trap+0x10/0x10
 ? report_bug+0x3cd/0x500
 ? handle_invalid_op+0x34/0x40
 ? clear_inode+0x168/0x190
 ? exc_invalid_op+0x38/0x50
 ? asm_exc_invalid_op+0x1a/0x20
 ? clear_inode+0x57/0x190
 ? clear_inode+0x167/0x190
 ? clear_inode+0x168/0x190
 ? clear_inode+0x167/0x190
 jfs_evict_inode+0xb5/0x440
 ? __pfx_jfs_evict_inode+0x10/0x10
 evict+0x4ea/0x9b0
 ? __pfx_evict+0x10/0x10
 ? iput+0x713/0xa50
 txUpdateMap+0x931/0xb10
 ? __pfx_txUpdateMap+0x10/0x10
 jfs_lazycommit+0x49a/0xb80
 ? _raw_spin_unlock_irqrestore+0x8f/0x140
 ? lockdep_hardirqs_on+0x99/0x150
 ? __pfx_jfs_lazycommit+0x10/0x10
 ? __pfx_default_wake_function+0x10/0x10
 ? __kthread_parkme+0x169/0x1d0
 ? __pfx_jfs_lazycommit+0x10/0x10
 kthread+0x2f2/0x390
 ? __pfx_jfs_lazycommit+0x10/0x10
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x4d/0x80
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>

This happens when 'clear_inode()' makes an attempt to finalize an underlying
JFS inode of unknown type. According to JFS layout description from
https://jfs.sourceforge.net/project/pub/jfslayout.pdf, inode types from 5 to
15 are reserved for future extensions and should not be encountered on a valid
filesystem. So add an extra check for valid inode type in 'copy_from_dinode()'.

## Which versions are affected by CVE-2025-37925?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-37925?

Apply the vendor's patch.

## Is CVE-2025-37925 being exploited?

There is no known exploitation of CVE-2025-37925 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-37925 and fix it if it is affected.

What it is: CVE-2025-37925 is a medium-severity vulnerability in Linux kernel, published on 18 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-37925 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-37925/ (Markdown: https://insights.sbomify.com/CVE-2025-37925/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37925
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37925
- OSV: https://osv.dev/vulnerability/CVE-2025-37925

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37925/
Summaries are generated and may contain mistakes; the official description above is the record.
