CVE-2023-53791

/// Technical description

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

md: fix warning for holder mismatch from export_rdev()

Commit a1d767191096 ("md: use mddev->external to select holder in

export_rdev()") fix the problem that 'claim_rdev' is used for

blkdev_get_by_dev() while 'rdev' is used for blkdev_put().

However, if mddev->external is changed from 0 to 1, then 'rdev' is used

for blkdev_get_by_dev() while 'claim_rdev' is used for blkdev_put(). And

this problem can be reporduced reliably by following:

New file: mdadm/tests/23rdev-lifetime

devname=${dev0##*/}

devt=`cat /sys/block/$devname/dev`

pid=""

runtime=2

clean_up_test() {

pill -9 $pid

echo clear > /sys/block/md0/md/array_state

}

trap 'clean_up_test' EXIT

add_by_sysfs() {

while true; do

echo $devt > /sys/block/md0/md/new_dev

done

}

remove_by_sysfs(){

while true; do

echo remove > /sys/block/md0/md/dev-${devname}/state

done

}

echo md0 > /sys/m

/// 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