Linux Kernel up to 5.12.4 enic enic_queue_wq_skb use after free

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 4.19.190/5.4.119/5.10.37/5.11.21/5.12.4. Affected is the function enic_queue_wq_skb of the component enic. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2021-46998. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 4.19.190/5.4.119/5.10.37/5.11.21/5.12.4 (Operating System). This vulnerability affects the function enic_queue_wq_skb of the component enic. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ethernet:enic: Fix a use after free bug in enic_hard_start_xmit In enic_hard_start_xmit, it calls enic_queue_wq_skb(). Inside enic_queue_wq_skb, if some error happens, the skb will be freed by dev_kfree_skb(skb). But the freed skb is still used in skb_tx_timestamp(skb). My patch makes enic_queue_wq_skb() return error and goto spin_unlock() incase of error. The solution is provided by Govind. See https://lkml.org/lkml/2021/4/30/961.

The weakness was shared 02/28/2024. The advisory is available at git.kernel.org. This vulnerability was named CVE-2021-46998 since 02/27/2024. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 06/21/2025).

The vulnerability scanner Nessus provides a plugin with the ID 239742 (TencentOS Server 2: kernel (TSSA-2024:1030)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.19.191, 5.4.120, 5.10.38, 5.11.22, 5.12.5 or 5.13 eliminates this vulnerability. Applying the patch 25a87b1f566b/f7f6f0777409/7afdd6aba95c/6892396ebf04/d90529392aaf/643001b47adc 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 vulnerability database at Tenable (239742). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.19.190
• 5.4.119
• 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
• 5.11.0
• 5.11.1
• 5.11.2
• 5.11.3
• 5.11.4
• 5.11.5
• 5.11.6
• 5.11.7
• 5.11.8
• 5.11.9
• 5.11.10
• 5.11.11
• 5.11.12
• 5.11.13
• 5.11.14
• 5.11.15
• 5.11.16
• 5.11.17
• 5.11.18
• 5.11.19
• 5.11.20
• 5.11.21
• 5.12.0
• 5.12.1
• 5.12.2
• 5.12.3
• 5.12.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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Exploitinginfo

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Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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