CVE-2023-46838

Linux: netback processing of zero-length transmit fragment

Description

Transmit requests in Xen's virtual network protocol can consist of multiple parts. While not really useful, except for the initial part any of them may be of zero length, i.e. carry no data at all. Besides a certain initial portion of the to be transferred data, these parts are directly translated into what Linux calls SKB fragments. Such converted request parts can, when for a particular SKB they are all of length zero, lead to a de-reference of NULL in core networking code.

Remediation

Workaround:

  • Using a userspace PV network backend (e.g. the qemu based "qnic" backend) will mitigate the problem. Using a dedicated network driver domain per guest will mitigate the problem.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.07%
Third-Party Advisory debian.org Third-Party Advisory debian.org Third-Party Advisory xenproject.org
Affected: Linux Linux
Published at:
Updated at:

References

Link Tags
https://xenbits.xenproject.org/xsa/advisory-448.html third party advisory patch
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZFYW6R64GPLUOXSQBJI3JBUX3HGLAYPP/ mailing list
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RGEKT4DKSDXDS34EL7M4UVJMMPH7Z3ZZ/ mailing list
https://lists.debian.org/debian-lts-announce/2024/06/msg00016.html third party advisory mailing list
https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html third party advisory mailing list

Frequently Asked Questions

What is the severity of CVE-2023-46838?
CVE-2023-46838 has been scored as a high severity vulnerability.
How to fix CVE-2023-46838?
As a workaround for remediating CVE-2023-46838: Using a userspace PV network backend (e.g. the qemu based "qnic" backend) will mitigate the problem. Using a dedicated network driver domain per guest will mitigate the problem.
Is CVE-2023-46838 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-46838 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-46838?
CVE-2023-46838 affects Linux Linux.
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