Описание
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Unregister redistributor for failed vCPU creation
Alex reports that syzkaller has managed to trigger a use-after-free when
tearing down a VM:
BUG: KASAN: slab-use-after-free in kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769
Read of size 8 at addr ffffff801c6890d0 by task syz.3.2219/10758
CPU: 3 UID: 0 PID: 10758 Comm: syz.3.2219 Not tainted 6.11.0-rc6-dirty #64
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x17c/0x1a8 arch/arm64/kernel/stacktrace.c:317
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x94/0xc0 lib/dump_stack.c:119
print_report+0x144/0x7a4 mm/kasan/report.c:377
kasan_report+0xcc/0x128 mm/kasan/report.c:601
__asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769
kvm_vm_release+0x4c/0x60 virt/kvm/kvm_main.c:1409
__fput+0x198/0x71c fs/file_table.c:422
____fput+0x20/0x30 fs/file_table.c:450
task_work_run+0x1cc/0x23c kernel/task_work.c:228
do_notify_resume+0x144/0x1a0 include/linux/resume_user_mode.h:50
el0_svc+0x64/0x68 arch/arm64/kernel/entry-common.c:169
el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
Upon closer inspection, it appears that we do not properly tear down the
MMIO registration for a vCPU that fails creation late in the game, e.g.
a vCPU w/ the same ID already exists in the VM.
It is important to consider the context of commit that introduced this bug
by moving the unregistration out of __kvm_vgic_vcpu_destroy(). That
change correctly sought to avoid an srcu v. config_lock inversion by
breaking up the vCPU teardown into two parts, one guarded by the
config_lock.
Fix the use-after-free while avoiding lock inversion by adding a
special-cased unregistration to __kvm_vgic_vcpu_destroy(). This is safe
because failed vCPUs are torn down outside of the config_lock.
A use-after-free vulnerability was found in the Linux kernel. Proper tear down of the MMIO registration for a vCPU that fails creation late in the game, for example
a vCPU w/ the same ID already existing in the VM, can lead to a deadlock condition.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| 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 | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected |
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Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Unregister redistributor for failed vCPU creation Alex reports that syzkaller has managed to trigger a use-after-free when tearing down a VM: BUG: KASAN: slab-use-after-free in kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769 Read of size 8 at addr ffffff801c6890d0 by task syz.3.2219/10758 CPU: 3 UID: 0 PID: 10758 Comm: syz.3.2219 Not tainted 6.11.0-rc6-dirty #64 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x17c/0x1a8 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x94/0xc0 lib/dump_stack.c:119 print_report+0x144/0x7a4 mm/kasan/report.c:377 kasan_report+0xcc/0x128 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769 kvm_vm_release+0x4c/0x60 virt/kvm/kvm_main.c:1409 __fput+0x198/0x71c fs/file_table.c:4...
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Unregister redistributor for failed vCPU creation Alex reports that syzkaller has managed to trigger a use-after-free when tearing down a VM: BUG: KASAN: slab-use-after-free in kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769 Read of size 8 at addr ffffff801c6890d0 by task syz.3.2219/10758 CPU: 3 UID: 0 PID: 10758 Comm: syz.3.2219 Not tainted 6.11.0-rc6-dirty #64 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x17c/0x1a8 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x94/0xc0 lib/dump_stack.c:119 print_report+0x144/0x7a4 mm/kasan/report.c:377 kasan_report+0xcc/0x128 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769 kvm_vm_release+0x4c/0x60 virt/kvm/kvm_main.c:140
In the Linux kernel, the following vulnerability has been resolved: K ...
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Unregister redistributor for failed vCPU creation Alex reports that syzkaller has managed to trigger a use-after-free when tearing down a VM: BUG: KASAN: slab-use-after-free in kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769 Read of size 8 at addr ffffff801c6890d0 by task syz.3.2219/10758 CPU: 3 UID: 0 PID: 10758 Comm: syz.3.2219 Not tainted 6.11.0-rc6-dirty #64 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x17c/0x1a8 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x94/0xc0 lib/dump_stack.c:119 print_report+0x144/0x7a4 mm/kasan/report.c:377 kasan_report+0xcc/0x128 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769 kvm_vm_release+0x4c/0x60 virt/kvm/kvm_main.c:...
Уязвимость функции __kvm_vgic_vcpu_destroy() модуля arch/arm64/kvm/vgic/vgic-init.c ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации
5.5 Medium
CVSS3