Логотип exploitDog
Консоль
Логотип exploitDog

exploitDog

nvd логотип

CVE-2021-47396

Опубликовано: 21 мая 2024
Источник: nvd
CVSS3: 5.5
EPSS Низкий

Описание

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

mac80211-hwsim: fix late beacon hrtimer handling

Thomas explained in https://lore.kernel.org/r/87mtoeb4hb.ffs@tglx that our handling of the hrtimer here is wrong: If the timer fires late (e.g. due to vCPU scheduling, as reported by Dmitry/syzbot) then it tries to actually rearm the timer at the next deadline, which might be in the past already:

1 2 3 N N+1 | | | ... | |

^ intended to fire here (1) ^ next deadline here (2) ^ actually fired here

The next time it fires, it's later, but will still try to schedule for the next deadline (now 3), etc. until it catches up with N, but that might take a long time, causing stalls etc.

Now, all of this is simulation, so we just have to fix it, but note that the behaviour is wrong even per spec, since there's no value then in sending all those beacons unali

Уязвимые конфигурации

Конфигурация 1

Одно из

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 3.9 (включая) до 5.4.151 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 5.5 (включая) до 5.10.71 (исключая)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Версия от 5.11 (включая) до 5.14.10 (исключая)
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*

EPSS

Процентиль: 3%
0.00015
Низкий

5.5 Medium

CVSS3

Дефекты

NVD-CWE-noinfo

Связанные уязвимости

CVSS3: 5.5
ubuntu
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: mac80211-hwsim: fix late beacon hrtimer handling Thomas explained in https://lore.kernel.org/r/87mtoeb4hb.ffs@tglx that our handling of the hrtimer here is wrong: If the timer fires late (e.g. due to vCPU scheduling, as reported by Dmitry/syzbot) then it tries to actually rearm the timer at the next deadline, which might be in the past already: 1 2 3 N N+1 | | | ... | | ^ intended to fire here (1) ^ next deadline here (2) ^ actually fired here The next time it fires, it's later, but will still try to schedule for the next deadline (now 3), etc. until it catches up with N, but that might take a long time, causing stalls etc. Now, all of this is simulation, so we just have to fix it, but note that the behaviour is wrong even per spec, since there's no value then in sending all those beacons unaligned - they should be aligned to the TBTT (1, 2, 3, ... ...

CVSS3: 4.4
redhat
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: mac80211-hwsim: fix late beacon hrtimer handling Thomas explained in https://lore.kernel.org/r/87mtoeb4hb.ffs@tglx that our handling of the hrtimer here is wrong: If the timer fires late (e.g. due to vCPU scheduling, as reported by Dmitry/syzbot) then it tries to actually rearm the timer at the next deadline, which might be in the past already: 1 2 3 N N+1 | | | ... | | ^ intended to fire here (1) ^ next deadline here (2) ^ actually fired here The next time it fires, it's later, but will still try to schedule for the next deadline (now 3), etc. until it catches up with N, but that might take a long time, causing stalls etc. Now, all of this is simulation, so we just have to fix it, but note that the behaviour is wrong even per spec, since there's no value then in sending all those beacons unaligned - they should be aligned to the TBTT (1, 2, 3, ... ...

CVSS3: 5.5
debian
больше 1 года назад

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

CVSS3: 5.5
github
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: mac80211-hwsim: fix late beacon hrtimer handling Thomas explained in https://lore.kernel.org/r/87mtoeb4hb.ffs@tglx that our handling of the hrtimer here is wrong: If the timer fires late (e.g. due to vCPU scheduling, as reported by Dmitry/syzbot) then it tries to actually rearm the timer at the next deadline, which might be in the past already: 1 2 3 N N+1 | | | ... | | ^ intended to fire here (1) ^ next deadline here (2) ^ actually fired here The next time it fires, it's later, but will still try to schedule for the next deadline (now 3), etc. until it catches up with N, but that might take a long time, causing stalls etc. Now, all of this is simulation, so we just have to fix it, but note that the behaviour is wrong even per spec, since there's no value then in sending all those beacons un...

CVSS3: 5.5
fstec
больше 4 лет назад

Уязвимость функции mac80211_hwsim_beacon() модуля drivers/net/wireless/mac80211_hwsim.c драйвера поддержки адаптеров беспроводной связи ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

EPSS

Процентиль: 3%
0.00015
Низкий

5.5 Medium

CVSS3

Дефекты

NVD-CWE-noinfo