CVE-2023-54021
Published Dec 24, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: set goal start correctly in ext4_mb_normalize_request We need to set ac_g_ex to notify the goal start used in ext4_mb_find_by_goal. Set ac_g_ex instead of ac_f_ex in ext4_mb_normalize_request. Besides we should assure goal start is in range [first_data_block, blocks_count) as ext4_mb_initialize_context does. [ Added a check to make sure size is less than ar->pright; otherwise we could end up passing an underflowed value of ar->pright - size to ext4_get_group_no_and_offset(), which will trigger a BUG_ON later on. - TYT ]
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References
Other References
https://git.kernel.org/stable/c/2479bb6cbdb4d56b807bbe5229e3e26a6f1f4530
https://git.kernel.org/stable/c/390eee955d4de4662db5e3e9e9a9eae020432cb7
https://git.kernel.org/stable/c/3ca3005b502ca8ea87d6a344323b179b48c4e4a3
https://git.kernel.org/stable/c/abb330ffaa3a0ae7ce632e28c9260b461c01f19f
https://git.kernel.org/stable/c/b07ffe6927c75d99af534d685282ea188d9f71a6
https://git.kernel.org/stable/c/bc4a3e1d07a86ae5845321d371190244acacb2f2
https://git.kernel.org/stable/c/c6bee8970075b256fc1b07bf4873049219380818
https://git.kernel.org/stable/c/cee78217a7ae72d11c2e21e1a5263b8044489823
Frequently Asked Questions
What is CVE-2023-54021? +
In the Linux kernel, the following vulnerability has been resolved:
ext4: set goal start correctly in ext4_mb_normalize_request
We need to set ac_g_ex to notify the goal start used in
ext4_mb_find_by_goal. Set ac_g_ex instead of ac_f_ex in
ext4_mb_normalize_request.
Besides we should assure goal start is in range [first_data_block,
blocks_count) as ext4_mb_initialize_context does.
[ Added a check to make sure size is less than ar->pright; otherwise
we could end up passing an underflowed value of ar->pright - size to
ext4_get_group_no_and_offset(), which will trigger a BUG_ON later on.
- TYT ]
How do I check if I'm vulnerable to CVE-2023-54021? +
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.