kernel KVM before versions kernel 4.16, kernel 4.16-rc7, kernel 4.17-rc1, kernel 4.17-rc2 and kernel 4.17-rc3 is vulnerable to a flaw in the way the Linux kernel's KVM hypervisor handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction after the stack switch is executed. An unprivileged KVM guest user could use this flaw to crash the guest or, potentially, escalate their privileges in the guest.

A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A; section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF) system flag (SDM Vol. 3A; section 2.3). If the instruction following the MOV to SS or POP to SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that t...

ELSA-2018-4219: kernel security update (IMPORTANT)

ELSA-2018-4098: Unbreakable Enterprise kernel security update (IMPORTANT)

ELSA-2018-4097: Unbreakable Enterprise kernel security update (IMPORTANT)

Уязвимость ядра операционных систем Linux, Windows, Ubuntu, Debian GNU/Linux, Red Hat Enterprise Linux, macOS, EulerOS, позволяющая нарушителю повысить свои привилегии

Security update for the Linux Kernel (Live Patch 33 for SLE 12)

Security update for the Linux Kernel (Live Patch 26 for SLE 12 SP1)

Security update for the Linux Kernel (Live Patch 27 for SLE 12)

Security update for the Linux Kernel (Live Patch 21 for SLE 12 SP1)

Security update for the Linux Kernel (Live Patch 31 for SLE 12)

Security update for the Linux Kernel (Live Patch 20 for SLE 12 SP1)

Security update for the Linux Kernel (Live Patch 25 for SLE 12)

Security update for the Linux Kernel (Live Patch 28 for SLE 12)

Security update for the Linux Kernel (Live Patch 23 for SLE 12 SP1)

Security update for the Linux Kernel (Live Patch 22 for SLE 12)

Security update for the Linux Kernel (Live Patch 30 for SLE 12)

Security update for the Linux Kernel (Live Patch 19 for SLE 12 SP1)

Security update for the Linux Kernel (Live Patch 18 for SLE 12 SP1)

Security update for the Linux Kernel (Live Patch 24 for SLE 12)