Описание
In the Linux kernel, the following vulnerability has been resolved:
xen-netfront: Fix NULL sring after live migration
A NAPI is setup for each network sring to poll data to kernel
The sring with source host is destroyed before live migration and
new sring with target host is setup after live migration.
The NAPI for the old sring is not deleted until setup new sring
with target host after migration. With busy_poll/busy_read enabled,
the NAPI can be polled before got deleted when resume VM.
BUG: unable to handle kernel NULL pointer dereference at
0000000000000008
IP: xennet_poll+0xae/0xd20
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
Call Trace:
finish_task_switch+0x71/0x230
timerqueue_del+0x1d/0x40
hrtimer_try_to_cancel+0xb5/0x110
xennet_alloc_rx_buffers+0x2a0/0x2a0
napi_busy_loop+0xdb/0x270
sock_poll+0x87/0x90
do_sys_poll+0x26f/0x580
tracing_map_insert+0x1d4/0x2f0
event_hist_trigger+0x14a/0x260
finish_task_switch+0x71/0x230
__schedule+0x256/0x890
recalc_sigpending+0x1b/0x50
xen_sched_clock+0x15/0x20
__rb_reserve_next+0x12d/0x140
ring_buffer_lock_reserve+0x123/0x3d0
event_triggers_call+0x87/0xb0
trace_event_buffer_commit+0x1c4/0x210
xen_clocksource_get_cycles+0x15/0x20
ktime_get_ts64+0x51/0xf0
SyS_ppoll+0x160/0x1a0
SyS_ppoll+0x160/0x1a0
do_syscall_64+0x73/0x130
entry_SYSCALL_64_after_hwframe+0x41/0xa6
...
RIP: xennet_poll+0xae/0xd20 RSP: ffffb4f041933900
CR2: 0000000000000008
---[ end trace f8601785b354351c ]---
xen frontend should remove the NAPIs for the old srings before live
migration as the bond srings are destroyed
There is a tiny window between the srings are set to NULL and
the NAPIs are disabled, It is safe as the NAPI threads are still
frozen at that time
A flaw was found in the Linux kernel's xen-netfront component. During a live migration of a virtual machine, the Networked Asynchronous Packet Interface (NAPI) for the old network shared ring (sring) is not properly removed before a new one is established. A local attacker with low privileges could exploit this timing issue by enabling busy_poll or busy_read when resuming a virtual machine. This can lead to a NULL pointer dereference, causing a system crash and a denial of service.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not 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 | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | ||
| Red Hat Enterprise Linux 8 | kernel | Will not fix | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Will not fix | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Will not fix | ||
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:6966 | 13.05.2025 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:6966 | 13.05.2025 |
Показывать по
Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: xen-netfront: Fix NULL sring after live migration A NAPI is setup for each network sring to poll data to kernel The sring with source host is destroyed before live migration and new sring with target host is setup after live migration. The NAPI for the old sring is not deleted until setup new sring with target host after migration. With busy_poll/busy_read enabled, the NAPI can be polled before got deleted when resume VM. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: xennet_poll+0xae/0xd20 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Call Trace: finish_task_switch+0x71/0x230 timerqueue_del+0x1d/0x40 hrtimer_try_to_cancel+0xb5/0x110 xennet_alloc_rx_buffers+0x2a0/0x2a0 napi_busy_loop+0xdb/0x270 sock_poll+0x87/0x90 do_sys_poll+0x26f/0x580 tracing_map_insert+0x1d4/0x2f0 event_hist_trigger+0x14a/0x260 finish_task_switch+0x71/0x230 __schedule+0x256/0x890 recalc_sigpending+0x1b/0x50 xen_sched_clock+0...
In the Linux kernel, the following vulnerability has been resolved: xen-netfront: Fix NULL sring after live migration A NAPI is setup for each network sring to poll data to kernel The sring with source host is destroyed before live migration and new sring with target host is setup after live migration. The NAPI for the old sring is not deleted until setup new sring with target host after migration. With busy_poll/busy_read enabled, the NAPI can be polled before got deleted when resume VM. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: xennet_poll+0xae/0xd20 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Call Trace: finish_task_switch+0x71/0x230 timerqueue_del+0x1d/0x40 hrtimer_try_to_cancel+0xb5/0x110 xennet_alloc_rx_buffers+0x2a0/0x2a0 napi_busy_loop+0xdb/0x270 sock_poll+0x87/0x90 do_sys_poll+0x26f/0x580 tracing_map_insert+0x1d4/0x2f0 event_hist_trigger+0x14a/0x260 finish_task_switch+0x71/0x230 __schedule+0x256/0x890 recalc_sigpending+0x1b/0x50 xen
In the Linux kernel, the following vulnerability has been resolved: x ...
In the Linux kernel, the following vulnerability has been resolved: xen-netfront: Fix NULL sring after live migration A NAPI is setup for each network sring to poll data to kernel The sring with source host is destroyed before live migration and new sring with target host is setup after live migration. The NAPI for the old sring is not deleted until setup new sring with target host after migration. With busy_poll/busy_read enabled, the NAPI can be polled before got deleted when resume VM. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: xennet_poll+0xae/0xd20 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Call Trace: finish_task_switch+0x71/0x230 timerqueue_del+0x1d/0x40 hrtimer_try_to_cancel+0xb5/0x110 xennet_alloc_rx_buffers+0x2a0/0x2a0 napi_busy_loop+0xdb/0x270 sock_poll+0x87/0x90 do_sys_poll+0x26f/0x580 tracing_map_insert+0x1d4/0x2f0 event_hist_trigger+0x14a/0x260 finish_task_switch+0x71/0x230 __schedule+0x256/0x890 recalc_sigpending+0x1b/0x50 ...
Уязвимость компонента xen-netfront ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании
EPSS
5.5 Medium
CVSS3