CVE-2021-47105: linux kernel — Exploit & Fix

Description

In the Linux kernel, the following vulnerability has been resolved: ice: xsk: return xsk buffers back to pool when cleaning the ring Currently we only NULL the xdp_buff pointer in the internal SW ring but we never give it back to the xsk buffer pool. This means that buffers can be leaked out of the buff pool and never be used again. Add missing xsk_buff_free() call to the routine that is supposed to clean the entries that are left in the ring so that these buffers in the umem can be used by other sockets. Also, only go through the space that is actually left to be cleaned instead of a whole ring.

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CVSS v3.1 Score

5.5

MEDIUM

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

Weakness Type (CWE)

CWE-401 CWE-401

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.5 — 5.15.12
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/ad6d20da2cfbe14b7b1200d15f39e65988b0b9e8 https://git.kernel.org/stable/c/afe8a3ba85ec2a6b6849367e25c06a2f8e0ddd05 https://git.kernel.org/stable/c/ad6d20da2cfbe14b7b1200d15f39e65988b0b9e8 https://git.kernel.org/stable/c/afe8a3ba85ec2a6b6849367e25c06a2f8e0ddd05

Exploits

https://git.kernel.org/stable/c/ad6d20da2cfbe14b7b1200d15f39e65988b0b9e8 https://git.kernel.org/stable/c/afe8a3ba85ec2a6b6849367e25c06a2f8e0ddd05 https://git.kernel.org/stable/c/ad6d20da2cfbe14b7b1200d15f39e65988b0b9e8 https://git.kernel.org/stable/c/afe8a3ba85ec2a6b6849367e25c06a2f8e0ddd05

Frequently Asked Questions

What is CVE-2021-47105? +

In the Linux kernel, the following vulnerability has been resolved: ice: xsk: return xsk buffers back to pool when cleaning the ring Currently we only NULL the xdp_buff pointer in the internal SW ring but we never give it back to the xsk buffer pool. This means that buffers can be leaked out of the buff pool and never be used again. Add missing xsk_buff_free() call to the routine that is supposed to clean the entries that are left in the ring so that these buffers in the umem can be used by other sockets. Also, only go through the space that is actually left to be cleaned instead of a whole ring. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2021-47105? +

CVE-2021-47105 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2021-47105? +

CVE-2021-47105 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2021-47105? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2021-47105