Linux KernelOperating system · Linux

CVE-2021-47445

MEDIUM · 5.5 CVSS v3.1 Published 2024-05-22
Fix available
A fix is available. Upgrade to 4.4.290 / 4.9.288 or later.
See remediation →
57/100
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
In the Linux kernel, the following vulnerability has been resolved: drm/msm: Fix null pointer dereference on pointer edp The initialization of pointer dev dereferences pointer edp before edp is null checked, so there is a potential null pointer deference issue. Fix this by only dereferencing edp after edp has been null checked. Addresses-Coverity: ("Dereference before null check")

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-476

The code follows a pointer that is null, crashing the process. An attacker who can reliably trigger it turns the crash into a denial of service. The fix is checking for null before use and handling the failure path gracefully.

General guidance for the null pointer dereference 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:>= 4.0, < 4.4.290>= 4.5, < 4.9.288>= 4.10, < 4.14.252>= 4.15, < 4.19.213>= 4.20, < 5.4.155>= 5.5, < 5.10.75>= 5.11, < 5.14.14= 5.15

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
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 4.4.290 / 4.9.288 / 4.14.252 or later
Fixed in 4.4.2904.9.2884.14.252
Vendor patch git.kernel.org →
Recommended fix High confidence

4.4.290, 4.9.288, 4.14.252, or 4.19.213 (or later)

  1. Identify the current running kernel version using `uname -r`
  2. Determine which kernel branch you are running (4.4.x, 4.9.x, 4.14.x, or 4.19.x)
  3. Upgrade to a fixed kernel version: 4.4.290 or later, 4.9.288 or later, 4.14.252 or later, or 4.19.213 or later
  4. Update the package manager repository and install the new kernel package (e.g., `apt-get update && apt-get install linux-image-<version>` for Debian/Ubuntu, or `yum update kernel` for RHEL/CentOS)
  5. Reboot the system to load the new kernel
  6. Verify the new kernel is running using `uname -r` and confirm the version includes the fix
Caveat Kernel upgrades may require system reboot and could affect proprietary drivers or hardware-specific functionality; test in staging environment before production deployment

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

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-47445 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2021-47445 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
  • No spam, self-promotion, credentials, or personal data