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Linux KernelOperating system · Linux

CVE-2022-39842

MEDIUM · 6.1 CVSS v3.1 Published 2022-09-05
Fix available
A fix is available. Upgrade to 5.19 or later.
See remediation →
63/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered in the Linux kernel before 5.19. In pxa3xx_gcu_write in drivers/video/fbdev/pxa3xx-gcu.c, the count parameter has a type conflict of size_t versus int, causing an integer overflow and bypassing the size check. After that, because it is used as the third argument to copy_from_user(), a heap overflow may occur. NOTE: the original discoverer disputes that the overflow can actually happen.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-190

An arithmetic operation produces a value too large for its type and wraps around to an unexpected — often tiny or negative — number. That miscalculated value then drives a memory allocation or a bounds check, opening the door to corruption. The fix is checked arithmetic and validating sizes before they're used.

General guidance for the integer overflow class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:< 5.19= 5.19
Debian LinuxOperating system
Affected:= 10.0= 11.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.19 or later
Fixed in 5.19
Vendor patch github.com →
Recommended fix High confidence

Linux Kernel 5.19 or later; Debian 10/11 users should apply vendor updates

  1. Identify the current kernel version using `uname -r` or `cat /proc/version`
  2. For Debian 10 (Buster): Upgrade to a kernel version that includes the fix (kernel 5.19+ or a Debian-specific backported patch)
  3. For Debian 11 (Bullseye): Upgrade to a kernel version that includes the fix
  4. Update package lists: `apt update`
  5. Install the new kernel: `apt install linux-image-<version>` or `apt full-upgrade`
  6. Reboot the system to load the new kernel: `reboot`
  7. Verify the new kernel is running: `uname -r`
Caveat Major kernel upgrades may require rebuilding third-party kernel modules; verify hardware compatibility with newer kernel

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,850. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-39842 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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