Linux Kernel up to 5.16.9 net tun_dst_unclone memory leak

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.16.9. It has been rated as critical. This issue affects the function tun_dst_unclone of the component net. The manipulation leads to memory leak. This vulnerability is traded as CVE-2022-48809. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.16.9. This issue affects the function tun_dst_unclone of the component net. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: fix a memleak when uncloning an skb dst and its metadata When uncloning an skb dst and its associated metadata, a new dst+metadata is allocated and later replaces the old one in the skb. This is helpful to have a non-shared dst+metadata attached to a specific skb. The issue is the uncloned dst+metadata is initialized with a refcount of 1, which is increased to 2 before attaching it to the skb. When tun_dst_unclone returns, the dst+metadata is only referenced from a single place (the skb) while its refcount is 2. Its refcount will never drop to 0 (when the skb is consumed), leading to a memory leak. Fix this by removing the call to dst_hold in tun_dst_unclone, as the dst+metadata refcount is already 1.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2022-48809 since 07/16/2024. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 209785 (EulerOS Virtualization 2.12.0 : kernel (EulerOS-SA-2024-2781)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.9.302, 4.14.267, 4.19.230, 5.4.180, 5.10.101, 5.15.24 or 5.16.10 eliminates this vulnerability. Applying the patch 4ac84498fbe8/c1ff27d100e2/0be943916d78/a80817adc2a4/00e6d6c3bc14/fdcb263fa5cd/8b1087b998e2/9eeabdf17fa0 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 (209785). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.9.301
• 4.14.266
• 4.19.229
• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.4.179
• 5.5
• 5.6
• 5.7
• 5.8
• 5.9
• 5.10.100
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.16.0
• 5.16.1
• 5.16.2
• 5.16.3
• 5.16.4
• 5.16.5
• 5.16.6
• 5.16.7
• 5.16.8
• 5.16.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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