bpf: fix incorrect sign extension in check_alu_op()

[linux-2.6-microblaze.git] / kernel / bpf / verifier.c

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 625e358..c086010 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2408,7 +2408,13 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
                         * remember the value we stored into this reg
                         */
                        regs[insn->dst_reg].type = SCALAR_VALUE;
-                       __mark_reg_known(regs + insn->dst_reg, insn->imm);
+                       if (BPF_CLASS(insn->code) == BPF_ALU64) {
+                               __mark_reg_known(regs + insn->dst_reg,
+                                                insn->imm);
+                       } else {
+                               __mark_reg_known(regs + insn->dst_reg,
+                                                (u32)insn->imm);
+                       }
                }
 
        } else if (opcode > BPF_END) {