CVE-2022-48645

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net: enetc: deny offload of tc-based TSN features on VF interfaces

TSN features on the ENETC (taprio, cbs, gate, police) are configured

through a mix of command BD ring messages and port registers:

enetc_port_rd(), enetc_port_wr().

Port registers are a region of the ENETC memory map which are only

accessible from the PCIe Physical Function. They are not accessible from

the Virtual Functions.

Moreover, attempting to access these registers crashes the kernel:

$ echo 1 > /sys/bus/pci/devices/0000\:00\:00.0/sriov_numvfs

pci 0000:00:01.0: [1957:ef00] type 00 class 0x020001

fsl_enetc_vf 0000:00:01.0: Adding to iommu group 15

fsl_enetc_vf 0000:00:01.0: enabling device (0000 -> 0002)

fsl_enetc_vf 0000:00:01.0 eno0vf0: renamed from eth0

$ tc qdisc replace dev eno0vf0 root taprio num_tc 8 map 0 1 2 3 4 5 6 7 \

queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 0 \

sched-entry S 0x7f 900000 sched-entry S 0x80 100000 flags 0x

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References