Kernel crash via uninitialized extref name length
Published Jul 25, 2025 · Updated Aug 5, 2026
Use of uninitialized data in Linux btrfs allows local users to crash the kernel through a crafted extref during log replay. In __inode_add_ref(), a jump to the next label leaves victim_name.len unset, so the next loop iteration uses an undefined length and performs an invalid memory access. Local low-privileged access is required, and replay of the malformed filesystem log can cause a kernel crash; no network-reachable path is reported.
Summary
What happened
Use of uninitialized data in Linux btrfs allows local users to crash the kernel through a crafted extref during log replay. In __inode_add_ref(), a jump to the next label leaves victim_name.len unset, so the next loop iteration uses an undefined length and performs an invalid memory access. Local low-privileged access is required, and replay of the malformed filesystem log can cause a kernel crash; no network-reachable path is reported.
The record
- CVE
- CVE-2025-38382
- Published
- Jul 25, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-908
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 25, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=1cf474cd474bc5d3ef63086ffd009a87a5b7bb2e <539969fc472886a1d63565459514d47e27fef461
- Affected versionversion=6.1.57 <6.1.144
- Affected versionversion=6.2
- Affected versionversion=e43eec81c5167b655b72c781b0e75e62a05e415e <2d11d274e2e1d7c79e2ca8461ce3ff3a95c11171
- Affected versionversion=e43eec81c5167b655b72c781b0e75e62a05e415e <54a7081ed168b72a8a2d6ef4ba3a1259705a2926
- Affected versionversion=e43eec81c5167b655b72c781b0e75e62a05e415e <7ac790dc2ba00499a8d671d4a24de4d4ad27e234
- Affected versionversion=e43eec81c5167b655b72c781b0e75e62a05e415e <aee57a0293dca675637e5504709f9f8fd8e871be
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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