CVE-2021-26932 Other in n/a

Medium 5.5 Published 17 Feb 2021 Updated 3 Aug 2024

Linux kernel Xen backend drivers mishandle batch hypercall errors in PV mode, potentially causing resource leaks or inconsistent state.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2021-26932?

CVE-2021-26932 is a medium-severity vulnerability in Debian Debian Linux, published on 17 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c.

Which versions are affected by CVE-2021-26932?

It affects 8 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp Cloud Backup, Netapp Hci Compute Node, Netapp Hci H410c Firmware and 2 more.

How do I fix CVE-2021-26932?

Apply the vendor's patch.

Is CVE-2021-26932 being exploited?

There is no known exploitation of CVE-2021-26932 in the wild and no public exploit code.

All Debian Debian Linux vulnerabilities

Sources

Also known as DEBIAN-CVE-2021-26932, GHSA-w8vm-5jg7-3r38, UBUNTU-CVE-2021-26932.