CVE-2025-40179
Published Nov 12, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: verify orphan file size is not too big In principle orphan file can be arbitrarily large. However orphan replay needs to traverse it all and we also pin all its buffers in memory. Thus filesystems with absurdly large orphan files can lead to big amounts of memory consumed. Limit orphan file size to a sane value and also use kvmalloc() for allocating array of block descriptor structures to avoid large order allocations for sane but large orphan files.
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References
Other References
https://git.kernel.org/stable/c/0a6ce20c156442a4ce2a404747bb0fb05d54eeb3
https://git.kernel.org/stable/c/2b9da798ff0f4d026c5f0f815047393ebe7d8859
https://git.kernel.org/stable/c/304fc34ff6fc8261138fd81f119e024ac3a129e9
https://git.kernel.org/stable/c/566a1d6084563bd07433025aa23bcea4427de107
https://git.kernel.org/stable/c/95a21611b14ae0a401720645245a8db16f040995
https://git.kernel.org/stable/c/a2d803fab8a6c6a874277cb80156dc114db91921
Frequently Asked Questions
What is CVE-2025-40179? +
In the Linux kernel, the following vulnerability has been resolved:
ext4: verify orphan file size is not too big
In principle orphan file can be arbitrarily large. However orphan replay
needs to traverse it all and we also pin all its buffers in memory. Thus
filesystems with absurdly large orphan files can lead to big amounts of
memory consumed. Limit orphan file size to a sane value and also use
kvmalloc() for allocating array of block descriptor structures to avoid
large order allocations for sane but large orphan files.
How do I check if I'm vulnerable to CVE-2025-40179? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.