Local kernel crash via zero-length osnoise write
Published Sep 23, 2025 · Updated Sep 23, 2025
NULL pointer dereference in Linux 6.15 through 6.17-rc4 allows local users to crash the kernel through the osnoise tracefs interface. osnoise_cpus_write passes a ZERO_SIZE_PTR returned by kmalloc() for a zero-byte write to cpulist_parse(), which dereferences it in bitmap_parselist(). Write access to the osnoise cpus control file is required; the published reproduction ran as UID 0 and caused a kernel oops.
Summary
What happened
NULL pointer dereference in Linux 6.15 through 6.17-rc4 allows local users to crash the kernel through the osnoise tracefs interface. osnoise_cpus_write passes a ZERO_SIZE_PTR returned by kmalloc() for a zero-byte write to cpulist_parse(), which dereferences it in bitmap_parselist(). Write access to the osnoise cpus control file is required; the published reproduction ran as UID 0 and caused a kernel oops.
The record
- CVE
- CVE-2025-39887
- Published
- Sep 23, 2025
- Updated
- Sep 23, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 23, 2025CVE publishedPublication date reported by the CVE source.
- Sep 23, 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?
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- Affected versionversion=17f89102fe23d7389085a8820550df688f79888a <c1628c00c4351dd0727ef7f670694f68d9e663d8
- Affected versionversion=17f89102fe23d7389085a8820550df688f79888a <e33228a2cc7ff706ca88533464e8a3b525b961ed
- Affected versionversion=6.16
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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