CVE-2022-50356

Local kernel crash via SFB reset null dereference

Published Sep 17, 2025 · Updated Sep 17, 2025

Null pointer dereference in the Linux kernel SFB qdisc allows local users to crash the system through qdisc configuration. When sfb_init() fails during mqprio_init(), sfb_reset() passes its still-null q->qdisc member to qdisc_reset(), which dereferences qdisc->ops and triggers a general protection fault. Exploitation requires a local low-privileged user able to modify qdisc settings while SFB is the default qdisc and initialization fails; the reported consequence is a kernel crash, not data access or modification.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Null pointer dereference in the Linux kernel SFB qdisc allows local users to crash the system through qdisc configuration. When sfb_init() fails during mqprio_init(), sfb_reset() passes its still-null q->qdisc member to qdisc_reset(), which dereferences qdisc->ops and triggers a general protection fault. Exploitation requires a local low-privileged user able to modify qdisc settings while SFB is the default qdisc and initialization fails; the reported consequence is a kernel crash, not data access or modification.

The record

CVE
CVE-2022-50356
Published
Sep 17, 2025
Updated
Sep 17, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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.

  1. Affected versionversion=2.6.39
  2. Affected versionversion=e13e02a3c68d899169c78d9a18689bd73491d59a <2a3fc78210b9f0e85372a2435368962009f480fc
  3. Affected versionversion=e13e02a3c68d899169c78d9a18689bd73491d59a <723399af2795fb95687a531c9480464b5f489333
  4. Affected versionversion=e13e02a3c68d899169c78d9a18689bd73491d59a <c2e1e59d59fafe297779ceae1fe0e6fbebc3e745
  5. Affected versionversion=e13e02a3c68d899169c78d9a18689bd73491d59a <ded86c4191a3c17f8200d17a7d8a6f63b74554ae

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.39; version=e13e02a3c68d899169c78d9a18689bd73491d59a <2a3fc78210b9f0e85372a2435368962009f480fc; version=e13e02a3c68d899169c78d9a18689bd73491d59a <723399af2795fb95687a531c9480464b5f489333; version=e13e02a3c68d899169c78d9a18689bd73491d59a <c2e1e59d59fafe297779ceae1fe0e6fbebc3e745; version=e13e02a3c68d899169c78d9a18689bd73491d59a <ded86c4191a3c17f8200d17a7d8a6f63b74554ae

Published CVSS scores

5.5CanonicalCVSS: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

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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

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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