Kernel crash via partial page extraction
Published Oct 28, 2025 · Updated Oct 28, 2025
NULL pointer dereference in the Linux kernel TEE subsystem allows local users to crash the kernel through malformed shared-memory registration. register_shm_helper() accepts a short positive result from iov_iter_extract_pages() as complete, leaving missing page entries that later reach a NULL dereference. The path requires local access to TEE_IOC_SHM_REGISTER and a partly unmapped buffer; reaching it crashes the host rather than exposing data.
Summary
What happened
NULL pointer dereference in the Linux kernel TEE subsystem allows local users to crash the kernel through malformed shared-memory registration. register_shm_helper() accepts a short positive result from iov_iter_extract_pages() as complete, leaving missing page entries that later reach a NULL dereference. The path requires local access to TEE_IOC_SHM_REGISTER and a partly unmapped buffer; reaching it crashes the host rather than exposing data.
The record
- CVE
- CVE-2025-40031
- Published
- Oct 28, 2025
- Updated
- Oct 28, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 28, 2025CVE publishedPublication date reported by the CVE source.
- Oct 28, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.8
- Affected versionversion=7bdee41575919773818e525ea19e54eb817770af <6a7874ab814ce12003c46a92f7afc9b035c8e8e9
- Affected versionversion=7bdee41575919773818e525ea19e54eb817770af <9338093db954918558677a468d32e77041c65167
- Affected versionversion=7bdee41575919773818e525ea19e54eb817770af <d5cf5b37064b1699d946e8b7ab4ac7d7d101814c
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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