CVE-2021-47023

/// Technical description

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

net: marvell: prestera: fix port event handling on init

For some reason there might be a crash during ports creation if port

events are handling at the same time because fw may send initial

port event with down state.

The crash points to cancel_delayed_work() which is called when port went

is down. Currently I did not find out the real cause of the issue, so

fixed it by cancel port stats work only if previous port's state was up

& runnig.

The following is the crash which can be triggered:

[ 28.311104] Unable to handle kernel paging request at virtual address

000071775f776600

[ 28.319097] Mem abort info:

[ 28.321914] ESR = 0x96000004

[ 28.324996] EC = 0x25: DABT (current EL), IL = 32 bits

[ 28.330350] SET = 0, FnV = 0

[ 28.333430] EA = 0, S1PTW = 0

[ 28.336597] Data abort info:

[ 28.339499] ISV = 0, ISS = 0x00000004

[ 28.343362] CM = 0, WnR = 0

[ 28.346354] user pgtable: 4k pages,

/// 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