Описание
In the Linux kernel, the following vulnerability has been resolved:
scsi: ch: Do not keep references to data transfer element devices
ch_readconfig() looks up the scsi_device of every data transfer element
whose SCSI id the changer reports in READ ELEMENT STATUS, and stores it in
ch->dt[]. scsi_device_lookup() takes a reference, and nothing ever drops
it: ch_destroy() frees the array with kfree(). ch->dt[] is read nowhere
else - it only supplies the vendor, model and revision printed in the same
loop.
Once such a drive is removed, its scsi_device can never be released. It
stays on the host's device list at its address, so a new device there is
refused by anything that walks the list - target_core_pscsi reports
"scsi_device_get() failed for H:C:T:L" - and the low-level driver's module
can no longer be unloaded. Only a reboot recovers.
It shows with any changer that reports its drives' ids; with the mhvtl
virtual library (IBM 3573-TL personality), each create and remove of a
library with four drives leaves four references behind, counted by the
module's use count in lsmod. With ch not bound the count is unchanged, and
with this patch applied it is unchanged too.
Drop the reference as soon as the name has been printed, and remove the now
unused dt[] array. That also removes the array leaked when ch_probe() fails
after ch_readconfig().
The same leak was reported with an RFC patch in 2022, which was not merged.
A flaw was found in the Linux kernel's SCSI changer driver, which can lead to a Denial of Service (DoS). The driver retains unreleased device references after reading changer configuration data, preventing removed devices from being properly cleaned up. An attacker or local user interacting with SCSI media changer devices can exploit this reference count leak to block subsequent device registration and prevent driver module unloading, requiring a system reboot to recover.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected |
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Дополнительная информация
Статус:
2.3 Low
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: scsi: ch: Do not keep references to data transfer element devices ch_readconfig() looks up the scsi_device of every data transfer element whose SCSI id the changer reports in READ ELEMENT STATUS, and stores it in ch->dt[]. scsi_device_lookup() takes a reference, and nothing ever drops it: ch_destroy() frees the array with kfree(). ch->dt[] is read nowhere else - it only supplies the vendor, model and revision printed in the same loop. Once such a drive is removed, its scsi_device can never be released. It stays on the host's device list at its address, so a new device there is refused by anything that walks the list - target_core_pscsi reports "scsi_device_get() failed for H:C:T:L" - and the low-level driver's module can no longer be unloaded. Only a reboot recovers. It shows with any changer that reports its drives' ids; with the mhvtl virtual library (IBM 3573-TL personality), each create and remove of a library w...
In the Linux kernel, the following vulnerability has been resolved: scsi: ch: Do not keep references to data transfer element devices ch_readconfig() looks up the scsi_device of every data transfer element whose SCSI id the changer reports in READ ELEMENT STATUS, and stores it in ch->dt[]. scsi_device_lookup() takes a reference, and nothing ever drops it: ch_destroy() frees the array with kfree(). ch->dt[] is read nowhere else - it only supplies the vendor, model and revision printed in the same loop. Once such a drive is removed, its scsi_device can never be released. It stays on the host's device list at its address, so a new device there is refused by anything that walks the list - target_core_pscsi reports "scsi_device_get() failed for H:C:T:L" - and the low-level driver's module can no longer be unloaded. Only a reboot recovers. It shows with any changer that reports its drives' ids; with the mhvtl virtual library (IBM 3573-TL personality), each create and remove of a library
scsi: ch: Do not keep references to data transfer element devices
In the Linux kernel, the following vulnerability has been resolved: s ...
In the Linux kernel, the following vulnerability has been resolved: scsi: ch: Do not keep references to data transfer element devices ch_readconfig() looks up the scsi_device of every data transfer element whose SCSI id the changer reports in READ ELEMENT STATUS, and stores it in ch->dt[]. scsi_device_lookup() takes a reference, and nothing ever drops it: ch_destroy() frees the array with kfree(). ch->dt[] is read nowhere else - it only supplies the vendor, model and revision printed in the same loop. Once such a drive is removed, its scsi_device can never be released. It stays on the host's device list at its address, so a new device there is refused by anything that walks the list - target_core_pscsi reports "scsi_device_get() failed for H:C:T:L" - and the low-level driver's module can no longer be unloaded. Only a reboot recovers. It shows with any changer that reports its drives' ids; with the mhvtl virtual library (IBM 3573-TL personality), each create and remove of a libra...
2.3 Low
CVSS3