Kernel crash via zero framebuffer pixclock
Published Apr 24, 2026 · Updated Apr 24, 2026
Divide-by-zero in the sm750fb driver in Linux Kernel allows local users to crash the kernel via a zero pixclock in FBIOPUT_VSCREENINFO. hw_sm750_crtc_set_mode() passes the unvalidated pixclock to ps_to_hz(), which divides by that value and faults when it is zero. Exploitation requires local low-privilege access to the framebuffer ioctl on a system using the sm750fb driver, and the bounded impact is a kernel crash.
Summary
What happened
Divide-by-zero in the sm750fb driver in Linux Kernel allows local users to crash the kernel via a zero pixclock in FBIOPUT_VSCREENINFO. hw_sm750_crtc_set_mode() passes the unvalidated pixclock to ps_to_hz(), which divides by that value and faults when it is zero. Exploitation requires local low-privilege access to the framebuffer ioctl on a system using the sm750fb driver, and the bounded impact is a kernel crash.
The record
- CVE
- CVE-2026-31603
- Published
- Apr 24, 2026
- Updated
- Apr 24, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-369, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 24, 2026CVE publishedPublication date reported by the CVE source.
- Apr 24, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1412ba36597a82e928f20047f41d6c6582dafe8a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2f640c6043aeab31a2f607d7605271860c3b11df
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6144895a4335a2491c282931f1f2fa610b86339f
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <daf6733bd7c4c5015b431739ac29b0e29021096b
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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