Описание
prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel before 5.14.12 allows unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds write.
An out-of-bounds (OOB) memory write flaw was found in prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the bpf in the Linux kernel. In this flaw, the multiplication to calculate the size could lead to an integer overflow which could allow a local attacker, with a special user privilege, to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information.
Отчет
The default Red Hat Enterprise Linux kernel prevents unprivileged users from being able to use eBPF by the kernel.unprivileged_bpf_disabled sysctl. This would require a privileged user with CAP_SYS_ADMIN or root to be able to abuse this flaw reducing its attack space. For the Red Hat Enterprise Linux 7 the eBPF for unprivileged users is always disabled. For the Red Hat Enterprise Linux 8 to confirm the current state, inspect the sysctl with the command:
cat /proc/sys/kernel/unprivileged_bpf_disabled
The setting of 1 would mean that unprivileged users can not use eBPF, mitigating the flaw. A kernel update will be required to mitigate the flaw for the root or users with CAP_SYS_ADMIN capabilities.
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 5 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| 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 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Fixed | RHSA-2022:1975 | 10.05.2022 |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2022:1988 | 10.05.2022 |
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Дополнительная информация
Статус:
EPSS
7.8 High
CVSS3
Связанные уязвимости
prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel before 5.14.12 allows unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds write.
prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel before 5.14.12 allows unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds write.
prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kern ...
Security update for the Linux Kernel (Live Patch 7 for SLE 15 SP3)
EPSS
7.8 High
CVSS3