Описание
In the Linux kernel, the following vulnerability has been resolved:
dax: Fix dax_mapping_release() use after free
A CONFIG_DEBUG_KOBJECT_RELEASE test of removing a device-dax region
provider (like modprobe -r dax_hmem) yields:
kobject: 'mapping0' (ffff93eb460e8800): kobject_release, parent 0000000000000000 (delayed 2000)
[..]
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 23 PID: 282 at kernel/locking/lockdep.c:232 __lock_acquire+0x9fc/0x2260
[..]
RIP: 0010:__lock_acquire+0x9fc/0x2260
[..]
Call Trace:
[..]
lock_acquire+0xd4/0x2c0
? ida_free+0x62/0x130
_raw_spin_lock_irqsave+0x47/0x70
? ida_free+0x62/0x130
ida_free+0x62/0x130
dax_mapping_release+0x1f/0x30
device_release+0x36/0x90
kobject_delayed_cleanup+0x46/0x150
Due to attempting ida_free() on an ida object that has already been
freed. Devices typically only hold a reference on their parent while
registered. If a child needs a parent object to complete its release it
needs to hold a reference that it drops from its release callback.
Arrange for a dax_mapping to pin its parent dev_dax instance until
dax_mapping_release().
A use-after-free vulnerability was found in the Linux kernel's device-dax subsystem during mapping object cleanup. When removing a dax region provider, the child dax_mapping objects attempt to free their ID allocator after the parent dev_dax object has already been released. This causes ida_free to operate on freed memory, triggering lockdep warnings and potentially causing crashes or memory corruption, leading to denial of service.
Отчет
The device-dax subsystem manages mappings of persistent memory regions. The parent-child relationship between dev_dax instances and their dax_mapping children follows the typical device model pattern: children hold references to parents while registered. However, dax_mapping objects were violating this pattern. When kobject delayed cleanup triggered dax_mapping_release (potentially seconds after the mapping was logically removed), it called ida_free on an ida structure that was part of the now-freed parent dev_dax object. The freed parent's memory could have been reallocated for other purposes, making the ida_free operate on arbitrary data structures. The issue manifests clearly under CONFIG_DEBUG_KOBJECT_RELEASE testing, which delays kobject cleanup to expose such bugs. Under normal conditions it creates a window where use-after-free could occur. The fix ensures dax_mapping holds an explicit reference on its parent that's only dropped during the final release callback.
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-rt | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2024:9315 | 12.11.2024 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2024:9315 | 12.11.2024 |
Показывать по
Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: dax: Fix dax_mapping_release() use after free A CONFIG_DEBUG_KOBJECT_RELEASE test of removing a device-dax region provider (like modprobe -r dax_hmem) yields: kobject: 'mapping0' (ffff93eb460e8800): kobject_release, parent 0000000000000000 (delayed 2000) [..] DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 23 PID: 282 at kernel/locking/lockdep.c:232 __lock_acquire+0x9fc/0x2260 [..] RIP: 0010:__lock_acquire+0x9fc/0x2260 [..] Call Trace: <TASK> [..] lock_acquire+0xd4/0x2c0 ? ida_free+0x62/0x130 _raw_spin_lock_irqsave+0x47/0x70 ? ida_free+0x62/0x130 ida_free+0x62/0x130 dax_mapping_release+0x1f/0x30 device_release+0x36/0x90 kobject_delayed_cleanup+0x46/0x150 Due to attempting ida_free() on an ida object that has already been freed. Devices typically only hold a reference on their parent while registered. If a child needs a parent object to complete its release it needs to hold a reference that it drops from its release callback. A...
In the Linux kernel, the following vulnerability has been resolved: dax: Fix dax_mapping_release() use after free A CONFIG_DEBUG_KOBJECT_RELEASE test of removing a device-dax region provider (like modprobe -r dax_hmem) yields: kobject: 'mapping0' (ffff93eb460e8800): kobject_release, parent 0000000000000000 (delayed 2000) [..] DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 23 PID: 282 at kernel/locking/lockdep.c:232 __lock_acquire+0x9fc/0x2260 [..] RIP: 0010:__lock_acquire+0x9fc/0x2260 [..] Call Trace: <TASK> [..] lock_acquire+0xd4/0x2c0 ? ida_free+0x62/0x130 _raw_spin_lock_irqsave+0x47/0x70 ? ida_free+0x62/0x130 ida_free+0x62/0x130 dax_mapping_release+0x1f/0x30 device_release+0x36/0x90 kobject_delayed_cleanup+0x46/0x150 Due to attempting ida_free() on an ida object that has already been freed. Devices typically only hold a reference on their parent while registered. If a child needs a parent object to complete its release it needs to hold a reference that it drops
In the Linux kernel, the following vulnerability has been resolved: d ...
In the Linux kernel, the following vulnerability has been resolved: dax: Fix dax_mapping_release() use after free A CONFIG_DEBUG_KOBJECT_RELEASE test of removing a device-dax region provider (like modprobe -r dax_hmem) yields: kobject: 'mapping0' (ffff93eb460e8800): kobject_release, parent 0000000000000000 (delayed 2000) [..] DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 23 PID: 282 at kernel/locking/lockdep.c:232 __lock_acquire+0x9fc/0x2260 [..] RIP: 0010:__lock_acquire+0x9fc/0x2260 [..] Call Trace: <TASK> [..] lock_acquire+0xd4/0x2c0 ? ida_free+0x62/0x130 _raw_spin_lock_irqsave+0x47/0x70 ? ida_free+0x62/0x130 ida_free+0x62/0x130 dax_mapping_release+0x1f/0x30 device_release+0x36/0x90 kobject_delayed_cleanup+0x46/0x150 Due to attempting ida_free() on an ida object that has already been freed. Devices typically only hold a reference on their parent while registered. If a child needs a parent object to complete its release it needs to hold a reference that it dro...
EPSS
5.5 Medium
CVSS3