CVE-2026-46079

/// Technical description

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

rbd: fix null-ptr-deref when device_add_disk() fails

do_rbd_add() publishes the device with device_add() before calling

device_add_disk(). If device_add_disk() fails after device_add()

succeeds, the error path calls rbd_free_disk() directly and then later

falls through to rbd_dev_device_release(), which calls rbd_free_disk()

again. This double teardown can leave blk-mq cleanup operating on

invalid state and trigger a null-ptr-deref in

__blk_mq_free_map_and_rqs(), reached from blk_mq_free_tag_set().

Fix this by following the normal remove ordering: call device_del()

before rbd_dev_device_release() when device_add_disk() fails after

device_add(). That keeps the teardown sequence consistent and avoids

re-entering disk cleanup through the wrong path.

The bug was first flagged by an experimental analysis tool we are

developing for kernel memory-management bugs while analyzing

v6.13-rc1. The tool is still under developme

/// 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