Описание
In the Linux kernel, the following vulnerability has been resolved:
net: sched: sfb: fix null pointer access issue when sfb_init() fails
When the default qdisc is sfb, if the qdisc of dev_queue fails to be
inited during mqprio_init(), sfb_reset() is invoked to clear resources.
In this case, the q->qdisc is NULL, and it will cause gpf issue.
The process is as follows:
qdisc_create_dflt()
sfb_init()
tcf_block_get() --->failed, q->qdisc is NULL
...
qdisc_put()
...
sfb_reset()
qdisc_reset(q->qdisc) --->q->qdisc is NULL
ops = qdisc->ops
The following is the Call Trace information:
general protection fault, probably for non-canonical address
0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
RIP: 0010:qdisc_reset+0x2b/0x6f0
Call Trace:
sfb_reset+0x37/0xd0
qdisc_reset+0xed/0x6f0
qdisc_destroy+0x82/0x4c0
qdisc_put+0x9e/0xb0
qdisc_create_dflt+0x2c3/0x4a0
mqprio_init+0xa71/0x1760
qdisc_create+0x3eb/0x1000
tc_modify_qdisc+0x408/0x1720
rtnetlink_rcv_msg+0x38e/0xac0
netlink_rcv_skb+0x12d/0x3a0
netlink_unicast+0x4a2/0x740
netlink_sendmsg+0x826/0xcc0
sock_sendmsg+0xc5/0x100
____sys_sendmsg+0x583/0x690
___sys_sendmsg+0xe8/0x160
__sys_sendmsg+0xbf/0x160
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f2164122d04
A null pointer dereference exists in the linux kernel, such that when sfb_init() fails qdisc is NULL, and it will cause gpf issue, leading to damage to the availability of the system.
Отчет
This vulnerability is rated Moderate rather than Low because a local user with privileges to manage network queuing disciplines (such as within a container namespace with CAP_NET_ADMIN) can trigger a kernel panic, resulting in a denial of service. The Stochastic Fair Blue (SFB) scheduler is not configured as the default queuing discipline in standard Red Hat Enterprise Linux installations, which restricts exposure to non-standard traffic control setups. The flaw cannot be exploited remotely and does not compromise system confidentiality or integrity.
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 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Will not fix | ||
| Red Hat Enterprise Linux 9 | kernel | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | kernel-rt | Fixed | RHSA-2025:23960 | 22.12.2025 |
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | kernel | Fixed | RHSA-2025:23947 | 22.12.2025 |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2023:7077 | 14.11.2023 |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | kernel | Fixed | RHSA-2025:23445 | 17.12.2025 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | kernel | Fixed | RHSA-2025:22752 | 04.12.2025 |
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Дополнительная информация
Статус:
7 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: net: sched: sfb: fix null pointer access issue when sfb_init() fails When the default qdisc is sfb, if the qdisc of dev_queue fails to be inited during mqprio_init(), sfb_reset() is invoked to clear resources. In this case, the q->qdisc is NULL, and it will cause gpf issue. The process is as follows: qdisc_create_dflt() sfb_init() tcf_block_get() --->failed, q->qdisc is NULL ... qdisc_put() ... sfb_reset() qdisc_reset(q->qdisc) --->q->qdisc is NULL ops = qdisc->ops The following is the Call Trace information: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] RIP: 0010:qdisc_reset+0x2b/0x6f0 Call Trace: <TASK> sfb_reset+0x37/0xd0 qdisc_reset+0xed/0x6f0 qdisc_destroy+0x82/0x4c0 qdisc_put+0x9e/0xb0 qdisc_create_dflt+0x2c3/0x4a0 mqprio_init+0xa71/0x1760 qdisc_create+0x3eb/0x1000 t...
In the Linux kernel, the following vulnerability has been resolved: net: sched: sfb: fix null pointer access issue when sfb_init() fails When the default qdisc is sfb, if the qdisc of dev_queue fails to be inited during mqprio_init(), sfb_reset() is invoked to clear resources. In this case, the q->qdisc is NULL, and it will cause gpf issue. The process is as follows: qdisc_create_dflt() sfb_init() tcf_block_get() --->failed, q->qdisc is NULL ... qdisc_put() ... sfb_reset() qdisc_reset(q->qdisc) --->q->qdisc is NULL ops = qdisc->ops The following is the Call Trace information: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] RIP: 0010:qdisc_reset+0x2b/0x6f0 Call Trace: <TASK> sfb_reset+0x37/0xd0 qdisc_reset+0xed/0x6f0 qdisc_destroy+0x82/0x4c0 qdisc_put+0x9e/0xb0 qdisc_create_dflt+0x2c3/0x4a0 mqprio_init+0xa71/0x1760 qdisc_crea
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: net: sched: sfb: fix null pointer access issue when sfb_init() fails When the default qdisc is sfb, if the qdisc of dev_queue fails to be inited during mqprio_init(), sfb_reset() is invoked to clear resources. In this case, the q->qdisc is NULL, and it will cause gpf issue. The process is as follows: qdisc_create_dflt() sfb_init() tcf_block_get() --->failed, q->qdisc is NULL ... qdisc_put() ... sfb_reset() qdisc_reset(q->qdisc) --->q->qdisc is NULL ops = qdisc->ops The following is the Call Trace information: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] RIP: 0010:qdisc_reset+0x2b/0x6f0 Call Trace: <TASK> sfb_reset+0x37/0xd0 qdisc_reset+0xed/0x6f0 qdisc_destroy+0x82/0x4c0 qdisc_put+0x9e/0xb0 qdisc_create_dflt+0x2c3/0x4a0 mqprio_init+0xa71/0x1760 qdisc_c...
Уязвимость функции sfb_reset() модуля net/sched/sch_sfb.c подсистемы управления трафиком net/sched ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации
7 High
CVSS3