Kernel crash via framebuffer refresh-rate integer overflow
Published Jul 10, 2025 · Updated Jul 14, 2026
Divide-by-zero in Linux and affected Siemens controller firmware allows local users to crash the kernel through crafted framebuffer mode input. The fb_find_mode_cvt() path doubles an interlaced refresh value of 0x80000000, wraps cvt.f_refresh to zero, and passes it to fb_cvt_hperiod() as a divisor. Low-privileged local access and control of the framebuffer mode are required; successful triggering produces a kernel oops and service interrupt.
Summary
What happened
Divide-by-zero in Linux and affected Siemens controller firmware allows local users to crash the kernel through crafted framebuffer mode input. The fb_find_mode_cvt() path doubles an interlaced refresh value of 0x80000000, wraps cvt.f_refresh to zero, and passes it to fb_cvt_hperiod() as a divisor. Low-privileged local access and control of the framebuffer mode are required; successful triggering produces a kernel oops and service interrupt.
The record
- CVE
- CVE-2025-38312
- Published
- Jul 10, 2025
- Updated
- Jul 14, 2026
- Vendor
- Siemens
- Product
- SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
- Classifications
- CWE-369, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 10, 2025CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
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- Affected versionversion=V3.1.5 <*
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What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
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Your stack
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