CVE-2025-38627
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-08-22

Last updated on: 2026-03-25

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic The decompress_io_ctx may be released asynchronously after I/O completion. If this file is deleted immediately after read, and the kworker of processing post_read_wq has not been executed yet due to high workloads, It is possible that the inode(f2fs_inode_info) is evicted and freed before it is used f2fs_free_dic. The UAF case as below: Thread A Thread B - f2fs_decompress_end_io - f2fs_put_dic - queue_work add free_dic work to post_read_wq - do_unlink - iput - evict - call_rcu This file is deleted after read. Thread C kworker to process post_read_wq - rcu_do_batch - f2fs_free_inode - kmem_cache_free inode is freed by rcu - process_scheduled_works - f2fs_late_free_dic - f2fs_free_dic - f2fs_release_decomp_mem read (dic->inode)->i_compress_algorithm This patch store compress_algorithm and sbi in dic to avoid inode UAF. In addition, the previous solution is deprecated in [1] may cause system hang. [1] https://lore.kernel.org/all/[email protected]
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Meta Information
Published
2025-08-22
Last Modified
2026-03-25
Generated
2026-05-07
AI Q&A
2025-08-22
EPSS Evaluated
2026-05-05
NVD
CVE-2025-38627
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a Use-After-Free (UAF) issue in the Linux kernel's f2fs filesystem compression code. Specifically, the f2fs_inode_info structure can be freed asynchronously after I/O completion if a file is deleted immediately after being read. Due to high workloads, the kernel worker thread that processes freeing this structure may not have run yet, causing the inode to be evicted and freed before it is used, leading to a UAF condition. The patch fixes this by storing necessary data in the decompression context to avoid referencing the freed inode.


How can this vulnerability impact me? :

This vulnerability can lead to a Use-After-Free condition in the kernel, which may cause system instability, crashes, or potentially allow an attacker to execute arbitrary code or escalate privileges by exploiting the freed memory. It can affect system reliability and security if an attacker can trigger the condition by deleting files immediately after reading them under high workload conditions.


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