CVE-2023-34319

Linux: buffer overrun in netback due to unusual packet

Published Sep 22, 2023 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
The fix for XSA-423 added logic to Linux'es netback driver to deal with
a frontend splitting a packet in a way such that not all of the headers
would come in one piece. Unfortunately the logic introduced there
didn't account for the extreme case of the entire packet being split
into as many pieces as permitted by the protocol, yet still being
smaller than the area that's specially dealt with to keep all (possible)
headers together. Such an unusual packet would therefore trigger a
buffer overrun in the driver.

Remediation

Vendor Workaround

Using another 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.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-3623-1 linux-5.10 security update
Debian DLA Debian DLA DLA-3710-1 linux security update
Debian DSA Debian DSA DSA-5480-1 linux security update
Debian DSA Debian DSA DSA-5492-1 linux security update
Ubuntu USN Ubuntu USN USN-6343-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6439-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6439-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6440-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6440-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6440-3 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6441-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6441-2 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-6441-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6442-1 Linux kernel (BlueField) vulnerabilities
Ubuntu USN Ubuntu USN USN-6444-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6444-2 Linux kernel (StarFive) vulnerabilities
Ubuntu USN Ubuntu USN USN-6445-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6445-2 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6446-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6446-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6446-3 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-6466-1 Linux kernel (NVIDIA) vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description The fix for XSA-423 added logic to Linux'es netback driver to deal with a frontend splitting a packet in a way such that not all of the headers would come in one piece. Unfortunately the logic introduced there didn't account for the extreme case of the entire packet being split into as many pieces as permitted by the protocol, yet still being smaller than the area that's specially dealt with to keep all (possible) headers together. Such an unusual packet would therefore trigger a buffer overrun in the driver. The fix for XSA-423 added logic to Linux'es netback driver to deal with a frontend splitting a packet in a way such that not all of the headers would come in one piece. Unfortunately the logic introduced there didn't account for the extreme case of the entire packet being split into as many pieces as permitted by the protocol, yet still being smaller than the area that's specially dealt with to keep all (possible) headers together. Such an unusual packet would therefore trigger a buffer overrun in the driver.
Weaknesses

Sources

Status
PUBLISHED
Assigner
XEN
Published
Updated
Oct 14, 2026, 11:17 PM
Reserved
Jun 1, 2023, 10:44 AM
Status
Modified
Published
Sep 22, 2023, 2:15 PM
Modified
Oct 15, 2026, 12:16 AM
Severity
Moderate
Public date
Aug 8, 2023, 12:00 AM