CVE-2022-49978

Kernel crash via zero framebuffer pixel clock

Published Jun 18, 2025 · Updated May 11, 2026

Divide-by-zero in the Linux kernel pm2fb driver allows local users to crash the kernel through a crafted framebuffer ioctl. pm2fb_check_var passes the user-controlled var->pixclock value to the PICOS2KHZ reciprocal calculation without first rejecting zero. Access to the pm2 framebuffer device and FBIOPUT_VSCREENINFO path is required, and a successful trigger interrupts host availability through a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Divide-by-zero in the Linux kernel pm2fb driver allows local users to crash the kernel through a crafted framebuffer ioctl. pm2fb_check_var passes the user-controlled var->pixclock value to the PICOS2KHZ reciprocal calculation without first rejecting zero. Access to the pm2 framebuffer device and FBIOPUT_VSCREENINFO path is required, and a successful trigger interrupts host availability through a kernel crash.

The record

CVE
CVE-2022-49978
Published
Jun 18, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-369, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 18, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0f1174f4972ea9fad6becf8881d71adca8e9ca91
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <19f953e7435644b81332dd632ba1b2d80b1e37af
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <34c3dea1189525cd533071ed5c176fc4ea8d982b
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3ec326a6a0d4667585ca595f438c7293e5ced7c4
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7d9591b32a9092fc6391a316b56e8016c6181c3d
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7f88cdfea8d7f4dbaf423d808241403b2bb945e4
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8fc778ee2fb2853f7a3531fa7273349640d8e4e9
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cb4bb011a683532841344ca7f281b5e04389b4f8
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0f1174f4972ea9fad6becf8881d71adca8e9ca91; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <19f953e7435644b81332dd632ba1b2d80b1e37af; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <34c3dea1189525cd533071ed5c176fc4ea8d982b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3ec326a6a0d4667585ca595f438c7293e5ced7c4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7d9591b32a9092fc6391a316b56e8016c6181c3d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7f88cdfea8d7f4dbaf423d808241403b2bb945e4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8fc778ee2fb2853f7a3531fa7273349640d8e4e9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cb4bb011a683532841344ca7f281b5e04389b4f8; version=2.6.12

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-369Divide By Zero
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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