CVE-2022-50552

/// Technical description

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

blk-mq: use quiesced elevator switch when reinitializing queues

The hctx's run_work may be racing with the elevator switch when

reinitializing hardware queues. The queue is merely frozen in this

context, but that only prevents requests from allocating and doesn't

stop the hctx work from running. The work may get an elevator pointer

that's being torn down, and can result in use-after-free errors and

kernel panics (example below). Use the quiesced elevator switch instead,

and make the previous one static since it is now only used locally.

nvme nvme0: resetting controller

nvme nvme0: 32/0/0 default/read/poll queues

BUG: kernel NULL pointer dereference, address: 0000000000000008

#PF: supervisor read access in kernel mode

#PF: error_code(0x0000) - not-present page

PGD 80000020c8861067 P4D 80000020c8861067 PUD 250f8c8067 PMD 0

Oops: 0000 [#1] SMP PTI

Workqueue: kblockd blk_mq_run_work_fn

RIP: 0010:kyber_

/// 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