Логотип exploitDog
Консоль
Логотип exploitDog

exploitDog

nvd логотип

CVE-2026-31421

Опубликовано: 13 апр. 2026
Источник: nvd
CVSS3: 5.5
EPSS Низкий

Описание

In the Linux kernel, the following vulnerability has been resolved:

net/sched: cls_fw: fix NULL pointer dereference on shared blocks

The old-method path in fw_classify() calls tcf_block_q() and dereferences q->handle. Shared blocks leave block->q NULL, causing a NULL deref when an empty cls_fw filter is attached to a shared block and a packet with a nonzero major skb mark is classified.

Reject the configuration in fw_change() when the old method (no TCA_OPTIONS) is used on a shared block, since fw_classify()'s old-method path needs block->q which is NULL for shared blocks.

The fixed null-ptr-deref calling stack: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:fw_classify (net/sched/cls_fw.c:81) Call Trace: tcf_classify (./include/net/tc_wrapper.h:197 net/sched/cls_api.c:1764 net/sched/cls_api.c:1860) tc_run (net/core/dev.c:4401) __dev_queue_xmit (net/core/dev.c:4535 net/core/dev.c:4790)

Уязвимые конфигурации

Конфигурация 1

Одно из

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 4.15 (включая) до 5.10.253 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 5.11 (включая) до 5.15.203 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 5.16 (включая) до 6.1.168 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 6.2 (включая) до 6.6.134 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 6.7 (включая) до 6.12.81 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 6.13 (включая) до 6.18.22 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 6.19 (включая) до 6.19.12 (исключая)
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

EPSS

Процентиль: 2%
0.0012
Низкий

5.5 Medium

CVSS3

Дефекты

CWE-476

Связанные уязвимости

CVSS3: 5.5
ubuntu
3 месяца назад

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_fw: fix NULL pointer dereference on shared blocks The old-method path in fw_classify() calls tcf_block_q() and dereferences q->handle. Shared blocks leave block->q NULL, causing a NULL deref when an empty cls_fw filter is attached to a shared block and a packet with a nonzero major skb mark is classified. Reject the configuration in fw_change() when the old method (no TCA_OPTIONS) is used on a shared block, since fw_classify()'s old-method path needs block->q which is NULL for shared blocks. The fixed null-ptr-deref calling stack: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:fw_classify (net/sched/cls_fw.c:81) Call Trace: tcf_classify (./include/net/tc_wrapper.h:197 net/sched/cls_api.c:1764 net/sched/cls_api.c:1860) tc_run (net/core/dev.c:4401) __dev_queue_xmit (net/core/dev.c:4535 net/core/dev.c:4790)

CVSS3: 5.5
redhat
4 месяца назад

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_fw: fix NULL pointer dereference on shared blocks The old-method path in fw_classify() calls tcf_block_q() and dereferences q->handle. Shared blocks leave block->q NULL, causing a NULL deref when an empty cls_fw filter is attached to a shared block and a packet with a nonzero major skb mark is classified. Reject the configuration in fw_change() when the old method (no TCA_OPTIONS) is used on a shared block, since fw_classify()'s old-method path needs block->q which is NULL for shared blocks. The fixed null-ptr-deref calling stack: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:fw_classify (net/sched/cls_fw.c:81) Call Trace: tcf_classify (./include/net/tc_wrapper.h:197 net/sched/cls_api.c:1764 net/sched/cls_api.c:1860) tc_run (net/core/dev.c:4401) __dev_queue_xmit (net/core/dev.c:4535 net/core/dev.c:4790)

CVSS3: 5.5
msrc
3 месяца назад

net/sched: cls_fw: fix NULL pointer dereference on shared blocks

CVSS3: 5.5
debian
3 месяца назад

In the Linux kernel, the following vulnerability has been resolved: n ...

CVSS3: 5.5
github
3 месяца назад

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_fw: fix NULL pointer dereference on shared blocks The old-method path in fw_classify() calls tcf_block_q() and dereferences q->handle. Shared blocks leave block->q NULL, causing a NULL deref when an empty cls_fw filter is attached to a shared block and a packet with a nonzero major skb mark is classified. Reject the configuration in fw_change() when the old method (no TCA_OPTIONS) is used on a shared block, since fw_classify()'s old-method path needs block->q which is NULL for shared blocks. The fixed null-ptr-deref calling stack: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:fw_classify (net/sched/cls_fw.c:81) Call Trace: tcf_classify (./include/net/tc_wrapper.h:197 net/sched/cls_api.c:1764 net/sched/cls_api.c:1860) tc_run (net/core/dev.c:4401) __dev_queue_xmit (net/core/dev.c:4535 net/core/dev.c:4790)

EPSS

Процентиль: 2%
0.0012
Низкий

5.5 Medium

CVSS3

Дефекты

CWE-476