PT-2025-39142 · Linux+5 · Linux Kernel+5
Published
2025-08-29
·
Updated
2026-05-07
·
CVE-2025-39885
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The Linux kernel contained a flaw in the OCFS2 implementation where a recursive semaphore deadlock could occur during a fiemap call. Specifically, the issue was detected by syzbot during a file system operation involving a specially crafted mmap file. The vulnerability arises from taking a read lock on the
ip alloc sem semaphore within ocfs2 fiemap() and subsequently attempting to acquire a write lock on the same semaphore within ocfs2 page mkwrite(), leading to a deadlock and filesystem hang. The ocfs2 fiemap() function takes a read lock of the ip alloc sem semaphore and calls fiemap fill next extent() to read the extent list. The user-supplied buffer then page faults, calling ocfs2 page mkwrite(), which attempts to take a write lock on the same semaphore.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
Improper Locking
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Weakness Enumeration
Related Identifiers
Affected Products
Debian
Linuxmint
Linux Kernel
Ocfs2
Suse
Ubuntu