CVE-2024-26899

Technical Description

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

block: fix deadlock between bd_link_disk_holder and partition scan

'open_mutex' of gendisk is used to protect open/close block devices. But

in bd_link_disk_holder(), it is used to protect the creation of symlink

between holding disk and slave bdev, which introduces some issues.

When bd_link_disk_holder() is called, the driver is usually in the process

of initialization/modification and may suspend submitting io. At this

time, any io hold 'open_mutex', such as scanning partitions, can cause

deadlocks. For example, in raid:

T1 T2

bdev_open_by_dev

lock open_mutex [1]

...

efi_partition

...

md_submit_bio

md_ioctl mddev_syspend

-> suspend all io

md_add_new_disk

bind_rdev_to_array

bd_link_disk_holder

try lock open_mutex [2]

md_handle_request

-> wait mddev_resume

T1 scan partition, T2 add a new device to raid. T1 waits for T2 to resume

mdde

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References