bpf: prevent speculative execution in eBPF interpreter
CVE-2017-5753
CVE-2017-5715
This adds a generic memory barrier before LD_IMM_DW and
LDX_MEM_B/H/W/DW eBPF instructions during eBPF program
execution in order to prevent speculative execution on out
of bound BFP_MAP array indexes. This way an arbitary kernel
memory is not exposed through side channel attacks.
For more details, please see this Google Project Zero report: tbd
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>