CVE-2024-50280

/// Technical description

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

dm cache: fix flushing uninitialized delayed_work on cache_ctr error

An unexpected WARN_ON from flush_work() may occur when cache creation

fails, caused by destroying the uninitialized delayed_work waker in the

error path of cache_create(). For example, the warning appears on the

superblock checksum error.

Reproduce steps:

dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"

dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"

dmsetup create corig --table "0 524288 linear /dev/sdc 262144"

dd if=/dev/urandom of=/dev/mapper/cmeta bs=4k count=1 oflag=direct

dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \

/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"

Kernel logs:

(snip)

WARNING: CPU: 0 PID: 84 at kernel/workqueue.c:4178 __flush_work+0x5d4/0x890

Fix by pulling out the cancel_delayed_work_sync() from the constructor's

error path. This patch doesn't affect the use-af

/// 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