CVE-2025-38627

f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic

HIGH
7.8
CVSS Score
Published: August 22, 2025 at 04:00 PM UTC
Updated: August 5, 2026 at 12:44 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%

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]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.0 ≤ v < 6.1.1756.0 ≤ v < 6.12.786.0 ≤ v < 6.16.16.0 ≤ v < 6.176.0 ≤ v < 6.6.1186.0bff139b49d9f70c1ac5384aac94554846aa834de
Vendor states this is fixed in 39868685c2a94a70762bc6d77dc81d781d05bff5 (fixed)
Vendor states this is fixed in 5d604d40cd3232b09cb339941ef958e49283ed0a (fixed)
Vendor states this is fixed in 74cbeeca4f16823ba58c882e1d8b836c0e39c93d (fixed)
Vendor states this is fixed in 8fae5b6addd5f6895e03797b56e3c7b9f9cd15c9 (fixed)
Vendor states this is fixed in cc81768212cdc509e5a986274db7bc24d18cde19 (fixed)
Vendor states this is fixed in 6.0 (unaffected)
Vendor states this is fixed in 6.1.175 (unaffected)
Vendor states this is fixed in 6.12.78 (unaffected)
Vendor states this is fixed in 6.16.1 (unaffected)
Vendor states this is fixed in 6.17 (unaffected)
Vendor states this is fixed in 6.6.118 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-416

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