Revert "bpf: prevent speculative execution in eBPF interpreter"

CVE-2017-5753 (revert embargoed)
CVE-2017-5715 (revert embargoed)

This reverts commit dd13f73106c260dea7a689d33d1457639af820aa.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 3f83c60e3e8669f81512f3ff05685e8e72366ef6..9a1bed1f30299b287b11de76f9300f42150f06f7 100644 (file)
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -33,7 +33,6 @@
 #include <linux/rcupdate.h>
 
 #include <asm/unaligned.h>
-#include <asm/barrier.h>
 
 /* Registers */
 #define BPF_R0 regs[BPF_REG_0]
@@ -921,7 +920,6 @@ select_insn:
                DST = IMM;
                CONT;
        LD_IMM_DW:
-               gmb();
                DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
                insn++;
                CONT;
@@ -1135,7 +1133,6 @@ out:
                *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
                CONT;                                                   \
        LDX_MEM_##SIZEOP:                                               \
-               gmb();                                                  \
                DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
                CONT;