CVE-2023-53323
BaseFortify
Publication date: 2025-09-16
Last updated on: 2025-12-10
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | From 5.15 (inc) to 6.1.40 (exc) |
| linux | linux_kernel | From 6.2 (inc) to 6.4.5 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-617 | The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability impact me? :
This vulnerability can cause a kernel crash (BUG) when truncating files on ext2 filesystems mounted on fsdax persistent memory devices. This can lead to system instability or denial of service, as the kernel encounters a critical error and stops normal operation.
Can you explain this vulnerability to me?
This vulnerability is in the Linux kernel's ext2 filesystem code related to DAX (Direct Access) on persistent memory devices. The issue occurs because the ext2_setsize function incorrectly handles cases where the length is page aligned, specifically when the length is zero. This leads to a call to ext2_get_blocks with max_blocks set to zero, triggering a kernel BUG. The problem arises from improper use of the PAGE_ALIGN macro and incorrect function calls in the ext2_setsize logic, which can cause the kernel to crash when truncating files on fsdax mounted pmem devices.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by attempting to trigger the bug on a filesystem using fsdax mounted pmem device with the following commands: 1. Create a file with dd: dd if=/dev/zero of=file count=1 bs=512 2. Truncate the file to zero size: truncate -s 0 file If the system is vulnerable, kernel logs will show a BUG_ON error in ext2_get_blocks with messages similar to: [79.525838] EXT2-fs (pmem0): DAX enabled. Warning: EXPERIMENTAL, use at your own risk [93.795102] kernel BUG at fs/ext2/inode.c:637! Checking kernel logs (e.g., using dmesg) after running these commands can help detect the vulnerability.
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include avoiding the use of ext2 filesystems on fsdax mounted pmem devices until the kernel patch fixing ext2_setsize is applied. Avoid truncating files to zero size on such setups as it triggers the bug. Applying the kernel update that fixes the ext2_setsize function to correctly handle page-aligned lengths will resolve the issue.