# CVE-2025-37806: fs/ntfs3: Keep write operations atomic

> A race condition in the Linux kernel NTFS3 driver allows a local attacker to trigger a NULL pointer dereference and crash the system.

- **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:** 8 May 2025
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2025-37806, DEBIAN-CVE-2025-37806, GHSA-wrch-r746-jf7c, ROOT-OS-DEBIAN-12-CVE-2025-37806, ROOT-OS-UBUNTU-2204-CVE-2025-37806, ROOT-OS-UBUNTU-2404-CVE-2025-37806, UBUNTU-CVE-2025-37806

## What is CVE-2025-37806?

CVE-2025-37806 is a medium-severity vulnerability in Linux kernel, published on 8 May 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:

fs/ntfs3: Keep write operations atomic

syzbot reported a NULL pointer dereference in __generic_file_write_iter. [1]

Before the write operation is completed, the user executes ioctl[2] to clear
the compress flag of the file, which causes the is_compressed() judgment to
return 0, further causing the program to enter the wrong process and call the
wrong ops ntfs_aops_cmpr, which triggers the null pointer dereference of
write_begin.

Use inode lock to synchronize ioctl and write to avoid this case.

[1]
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
  ESR = 0x0000000086000006
  EC = 0x21: IABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=000000011896d000
[0000000000000000] pgd=0800000118b44403, p4d=0800000118b44403, pud=0800000117517403, pmd=0000000000000000
Internal error: Oops: 0000000086000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 UID: 0 PID: 6427 Comm: syz-executor347 Not tainted 6.13.0-rc3-syzkaller-g573067a5a685 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : 0x0
lr : generic_perform_write+0x29c/0x868 mm/filemap.c:4055
sp : ffff80009d4978a0
x29: ffff80009d4979c0 x28: dfff800000000000 x27: ffff80009d497bc8
x26: 0000000000000000 x25: ffff80009d497960 x24: ffff80008ba71c68
x23: 0000000000000000 x22: ffff0000c655dac0 x21: 0000000000001000
x20: 000000000000000c x19: 1ffff00013a92f2c x18: ffff0000e183aa1c
x17: 0004060000000014 x16: ffff800083275834 x15: 0000000000000001
x14: 0000000000000000 x13: 0000000000000001 x12: ffff0000c655dac0
x11: 0000000000ff0100 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff80009d497980 x4 : ffff80009d497960 x3 : 0000000000001000
x2 : 0000000000000000 x1 : ffff0000e183a928 x0 : ffff0000d60b0fc0
Call trace:
 0x0 (P)
 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4156
 ntfs_file_write_iter+0x54c/0x630 fs/ntfs3/file.c:1267
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x920/0xcf4 fs/read_write.c:679
 ksys_write+0x15c/0x26c fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:739
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762

[2]
ioctl$FS_IOC_SETFLAGS(r0, 0x40086602, &(0x7f00000000c0)=0x20)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-37806?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-37806?

Apply the vendor's patch.

## Is CVE-2025-37806 being exploited?

There is no known exploitation of CVE-2025-37806 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-2025-37806 and fix it if it is affected.

What it is: CVE-2025-37806 is a medium-severity vulnerability in Linux kernel, published on 8 May 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-2025-37806 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-2025-37806/ (Markdown: https://insights.sbomify.com/CVE-2025-37806/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37806
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37806
- OSV: https://osv.dev/vulnerability/CVE-2025-37806

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37806/
Summaries are generated and may contain mistakes; the official description above is the record.