Уязвимость функции prctl ядра операционной системы Linux, позволяющая нарушителю получить доступ к защищаемой информации

Уязвимость функции r592_remove() в модуле drivers/memstick/host/r592.c ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность и доступность защищаемой информации

Уязвимость реализации файловой системы relayfs ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании или раскрыть защищаемую информацию

Уязвимость микропрограммного обеспечения процессоров AMD на базе микроархитектуры Zen2, позволяющая нарушителю отследить содержимого регистров во время выполнения других процессов на том же ядре CPU

The Linux kernel allows userspace processes to enable mitigations by calling prctl with PR_SET_SPECULATION_CTRL which disables the speculation feature as well as by using seccomp. We had noticed that on VMs of at least one major cloud provider, the kernel still left the victim process exposed to attacks in some cases even after enabling the spectre-BTI mitigation with prctl. The same behavior can be observed on a bare-metal machine when forcing the mitigation to IBRS on boot command line. This happened because when plain IBRS was enabled (not enhanced IBRS), the kernel had some logic that determined that STIBP was not needed. The IBRS bit implicitly protects against cross-thread branch target injection. However, with legacy IBRS, the IBRS bit was cleared on returning to userspace, due to performance reasons, which disabled the implicit STIBP and left userspace threads vulnerable to cross-thread branch target injection against which STIBP protects.

An issue in “Zen 2” CPUs, under specific microarchitectural circumstances, may allow an attacker to potentially access sensitive information.

A use-after-free flaw was found in r592_remove in drivers/memstick/host/r592.c in media access in the Linux Kernel. This flaw allows a local attacker to crash the system at device disconnect, possibly leading to a kernel information leak.

An out of bounds (OOB) memory access flaw was found in the Linux kernel in relay_file_read_start_pos in kernel/relay.c in the relayfs. This flaw could allow a local attacker to crash the system or leak kernel internal information.