# CVE-2023-53306: fsdax: force clear dirty mark if CoW

> A flaw in the Linux kernel's fsdax subsystem can trigger a kernel warning and potential crash during Copy-on-Write operations on XFS filesystems.

- **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:** 16 Sep 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53306, DEBIAN-CVE-2023-53306, GHSA-9247-9gc6-2w2p, UBUNTU-CVE-2023-53306

## What is CVE-2023-53306?

CVE-2023-53306 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Sep 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:

fsdax: force clear dirty mark if CoW

XFS allows CoW on non-shared extents to combat fragmentation[1].  The old
non-shared extent could be mwrited before, its dax entry is marked dirty. 

This results in a WARNing:

[   28.512349] ------------[ cut here ]------------
[   28.512622] WARNING: CPU: 2 PID: 5255 at fs/dax.c:390 dax_insert_entry+0x342/0x390
[   28.513050] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache netfs nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables
[   28.515462] CPU: 2 PID: 5255 Comm: fsstress Kdump: loaded Not tainted 6.3.0-rc1-00001-g85e1481e19c1-dirty #117
[   28.515902] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Arch Linux 1.16.1-1-1 04/01/2014
[   28.516307] RIP: 0010:dax_insert_entry+0x342/0x390
[   28.516536] Code: 30 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 8b 45 20 48 83 c0 01 e9 e2 fe ff ff 48 8b 45 20 48 83 c0 01 e9 cd fe ff ff <0f> 0b e9 53 ff ff ff 48 8b 7c 24 08 31 f6 e8 1b 61 a1 00 eb 8c 48
[   28.517417] RSP: 0000:ffffc9000845fb18 EFLAGS: 00010086
[   28.517721] RAX: 0000000000000053 RBX: 0000000000000155 RCX: 000000000018824b
[   28.518113] RDX: 0000000000000000 RSI: ffffffff827525a6 RDI: 00000000ffffffff
[   28.518515] RBP: ffffea00062092c0 R08: 0000000000000000 R09: ffffc9000845f9c8
[   28.518905] R10: 0000000000000003 R11: ffffffff82ddb7e8 R12: 0000000000000155
[   28.519301] R13: 0000000000000000 R14: 000000000018824b R15: ffff88810cfa76b8
[   28.519703] FS:  00007f14a0c94740(0000) GS:ffff88817bd00000(0000) knlGS:0000000000000000
[   28.520148] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   28.520472] CR2: 00007f14a0c8d000 CR3: 000000010321c004 CR4: 0000000000770ee0
[   28.520863] PKRU: 55555554
[   28.521043] Call Trace:
[   28.521219]  <TASK>
[   28.521368]  dax_fault_iter+0x196/0x390
[   28.521595]  dax_iomap_pte_fault+0x19b/0x3d0
[   28.521852]  __xfs_filemap_fault+0x234/0x2b0
[   28.522116]  __do_fault+0x30/0x130
[   28.522334]  do_fault+0x193/0x340
[   28.522586]  __handle_mm_fault+0x2d3/0x690
[   28.522975]  handle_mm_fault+0xe6/0x2c0
[   28.523259]  do_user_addr_fault+0x1bc/0x6f0
[   28.523521]  exc_page_fault+0x60/0x140
[   28.523763]  asm_exc_page_fault+0x22/0x30
[   28.524001] RIP: 0033:0x7f14a0b589ca
[   28.524225] Code: c5 fe 7f 07 c5 fe 7f 47 20 c5 fe 7f 47 40 c5 fe 7f 47 60 c5 f8 77 c3 66 0f 1f 84 00 00 00 00 00 40 0f b6 c6 48 89 d1 48 89 fa <f3> aa 48 89 d0 c5 f8 77 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90
[   28.525198] RSP: 002b:00007fff1dea1c98 EFLAGS: 00010202
[   28.525505] RAX: 000000000000001e RBX: 000000000014a000 RCX: 0000000000006046
[   28.525895] RDX: 00007f14a0c82000 RSI: 000000000000001e RDI: 00007f14a0c8d000
[   28.526290] RBP: 000000000000006f R08: 0000000000000004 R09: 000000000014a000
[   28.526681] R10: 0000000000000008 R11: 0000000000000246 R12: 028f5c28f5c28f5c
[   28.527067] R13: 8f5c28f5c28f5c29 R14: 0000000000011046 R15: 00007f14a0c946c0
[   28.527449]  </TASK>
[   28.527600] ---[ end trace 0000000000000000 ]---

To be able to delete this entry, clear its dirty mark before
invalidate_inode_pages2_range().

[1] https://lore.kernel.org/linux-xfs/20230321151339.GA11376@frogsfrogsfrogs/

## Which versions are affected by CVE-2023-53306?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53306?

Apply the vendor's patch.

## Is CVE-2023-53306 being exploited?

There is no known exploitation of CVE-2023-53306 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-2023-53306 and fix it if it is affected.

What it is: CVE-2023-53306 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Sep 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-2023-53306 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-2023-53306/ (Markdown: https://insights.sbomify.com/CVE-2023-53306/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53306
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53306
- OSV: https://osv.dev/vulnerability/CVE-2023-53306

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53306/
Summaries are generated and may contain mistakes; the official description above is the record.