Linux Kernel up to 5.12.8 mlx5e bond_enslave null pointer dereference

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 5.5 | $0-$5k | 0.00 |
Summary
A vulnerability identified as critical has been detected in Linux Kernel up to 5.7/5.8/5.10.41/5.12/5.12.8. This issue affects the function bond_enslave of the component mlx5e. This manipulation causes null pointer dereference.
This vulnerability appears as CVE-2021-47164. There is no available exploit.
You should upgrade the affected component.
Details
A vulnerability classified as critical was found in Linux Kernel up to 5.7/5.8/5.10.41/5.12/5.12.8. Affected by this vulnerability is the function bond_enslave of the component mlx5e. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix null deref accessing lag dev It could be the lag dev is null so stop processing the event. In bond_enslave() the active/backup slave being set before setting the upper dev so first event is without an upper dev. After setting the upper dev with bond_master_upper_dev_link() there is a second event and in that event we have an upper dev.
The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2021-47164. Technical details are known, but no exploit is available.
The vulnerability scanner Nessus provides a plugin with the ID 239841 (TencentOS Server 4: kernel (TSSA-2024:0960)), which helps to determine the existence of the flaw in a target environment.
Upgrading to version 5.10.42, 5.12.9 or 5.13 eliminates this vulnerability. Applying the patch 2e4b0b95a489/bdfd3593a824/83026d83186b is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.
The vulnerability is also documented in the databases at Tenable (239841) and CERT Bund (WID-SEC-2024-0699). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Affected
- Amazon Linux 2
- Red Hat Enterprise Linux
- Ubuntu Linux
- SUSE Linux
- Oracle Linux
- EMC Avamar
- Dell NetWorker
- Open Source Linux Kernel
- IBM Spectrum Protect Plus
Product
Type
Vendor
Name
Version
- 5.0
- 5.1
- 5.2
- 5.3
- 5.4
- 5.5
- 5.6
- 5.7
- 5.8
- 5.9
- 5.10
- 5.10.0
- 5.10.1
- 5.10.2
- 5.10.3
- 5.10.4
- 5.10.5
- 5.10.6
- 5.10.7
- 5.10.8
- 5.10.9
- 5.10.10
- 5.10.11
- 5.10.12
- 5.10.13
- 5.10.14
- 5.10.15
- 5.10.16
- 5.10.17
- 5.10.18
- 5.10.19
- 5.10.20
- 5.10.21
- 5.10.22
- 5.10.23
- 5.10.24
- 5.10.25
- 5.10.26
- 5.10.27
- 5.10.28
- 5.10.29
- 5.10.30
- 5.10.31
- 5.10.32
- 5.10.33
- 5.10.34
- 5.10.35
- 5.10.36
- 5.10.37
- 5.10.38
- 5.10.39
- 5.10.40
- 5.10.41
- 5.11
- 5.12
- 5.12.0
- 5.12.1
- 5.12.2
- 5.12.3
- 5.12.4
- 5.12.5
- 5.12.6
- 5.12.7
- 5.12.8
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔍VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 5.7VulDB Meta Temp Score: 5.5
VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv2
| AV | AC | Au | C | I | A |
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| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍
Exploiting
Class: Null pointer dereferenceCWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍
Physical: No
Local: No
Remote: Partially
Availability: 🔍
Status: Not defined
EPSS Score: 🔍
EPSS Percentile: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍
| 0-Day | Unlock | Unlock | Unlock | Unlock |
|---|---|---|---|---|
| Today | Unlock | Unlock | Unlock | Unlock |
Nessus ID: 239841
Nessus Name: TencentOS Server 4: kernel (TSSA-2024:0960)
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔍
Upgrade: Kernel 5.10.42/5.12.9/5.13
Patch: 2e4b0b95a489/bdfd3593a824/83026d83186b
Timeline
03/25/2024 🔍03/25/2024 🔍
03/25/2024 🔍
08/04/2025 🔍
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2021-47164 (🔍)
GCVE (CVE): GCVE-0-2021-47164
GCVE (VulDB): GCVE-100-257833
CERT Bund: WID-SEC-2024-0699 - Linux-Kernel: Mehrere Schwachstellen ermöglichen Denial of Service und unspezifische Angriffe
Entry
Created: 03/25/2024 10:30Updated: 08/04/2025 07:15
Changes: 03/25/2024 10:30 (57), 05/04/2024 12:26 (1), 06/19/2025 19:59 (3), 08/04/2025 07:15 (7)
Complete: 🔍
Cache ID: 216::103
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
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