| Description: | The x86/fpu (Floating Point Unit) subsystem in the Linux kernel before 4.13.5, when a processor supports the xsave feature but not the xsaves feature, does not correctly handle attempts to set reserved bits in the xstate header via the ptrace() or rt_sigreturn() system call, allowing local users to read the FPU registers of other processes on the system, related to arch/x86/kernel/fpu/regset.c and arch/x86/kernel/fpu/signal.c. Dmitry Vyukov discovered that the Floating Point Unit (fpu) subsystem in the Linux kernel did not properly handle attempts to set reserved bits in a task's extended state (xstate) area. A local attacker could use this to cause a denial of service (system crash).
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