Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2023-53323 — kernel

🟡 CVSS 5.5 — Medium ✅ No Known Exploit NVD
5.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

ext2/dax: Fix ext2_setsize when len is page aligned

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

ext2/dax: Fix ext2_setsize when len is page aligned

PAGE_ALIGN(x) macro gives the next highest value which is multiple of

pagesize. But if x is already page aligned then it simply returns x.

So, if x passed is 0 in dax_zero_range() function, that means the

length gets passed as 0 to ->iomap_begin().

In ext2 it then calls ext2_get_blocks -> max_blocks as 0 and hits bug_on

here in ext2_get_blocks().

BUG_ON(maxblocks == 0);

Instead we should be calling dax_truncate_page() here which takes

care of it. i.e. it only calls dax_zero_range if the offset is not

page/block aligned.

This can be easily triggered with following on fsdax mounted pmem

device.

dd if=/dev/zero of=file count=1 bs=512

truncate -s 0 file

[79.525838] EXT2-fs (pmem0): DAX enabled. Warning: EXPERIMENTAL, use at your own risk

[79.529376] ext2 filesystem being mounted at /mnt1/test supports timestamps until 2038 (0x7fffffff)

[93.793207] ------------[ cut here ]------------

[93.795102] kernel BUG at fs/ext2/inode.c:637!

[93.796904] invalid opcode: 0000 [#1] PREEMPT SMP PTI

[93.798659] CPU: 0 PID: 1192 Comm: truncate Not tainted 6.3.0-rc2-xfstests-00056-g131086faa369 #139

[93.806459] RIP: 0010:ext2_get_blocks.constprop.0+0x524/0x610

<...>

[93.835298] Call Trace:

[93.836253] <TASK>

[93.837103] ? lock_acquire+0xf8/0x110

[93.838479] ? d_lookup+0x69/0xd0

[93.839779] ext2_iomap_begin+0xa7/0x1c0

[93.841154] iomap_iter+0xc7/0x150

[93.842425] dax_zero_range+0x6e/0xa0

[93.843813] ext2_setsize+0x176/0x1b0

[93.845164] ext2_setattr+0x151/0x200

[93.846467] notify_change+0x341/0x4e0

[93.847805] ? lock_acquire+0xf8/0x110

[93.849143] ? do_truncate+0x74/0xe0

[93.850452] ? do_truncate+0x84/0xe0

[93.851739] do_truncate+0x84/0xe0

[93.852974] do_sys_ftruncate+0x2b4/0x2f0

[93.854404] do_syscall_64+0x3f/0x90

[93.855789] entry_SYSCALL_64_after_hwframe+0x72/0xdc

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: None.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

CVE-2023-53323 is recorded against 2 packages.

  • kernel (from 6.2.0 up to 6.4.5)
  • linux-kernel (from 6.2 up to 6.4.5)

Timeline and source

Published on 16 September 2025 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

Other advisories for this package

kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:

CVE-2023-53323 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Medium
CVSS Score 5.5
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-09-16
Updated 2026-08-20
Modified 2026-08-12

Affected Packages

Software From version Fixed in
kernel 6.2.0 6.4.5
linux-kernel 6.2 6.4.5

Similar Threats

Vulnerability Monitoring

Track new vulnerabilities in kernel

CVE-2023-53323 is rated CVSS 5.5 Medium. BotEraser monitors your WordPress installation and notifies you when software you use appears in our vulnerability database.

Set Up Free Alerts →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2023
✓