From: Daniel Borkmann <daniel@iogearbox.net>
Date: Sun, 11 Jun 2017 00:50:42 +0200
Subject: bpf: reset id on CONST_IMM transition
Patch-mainline: v4.13-rc1
Git-commit: 4a2ff55aa4946b036b87572976cbfc6ab244c497
References: bsc#1056787

Whenever we set the register to the type CONST_IMM, we currently don't
reset the id to 0. id member is not used in CONST_IMM case, so don't
let it become stale, where pruning won't be able to match later on.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 kernel/bpf/verifier.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2049,6 +2049,7 @@ static int check_alu_op(struct bpf_verif
 			 */
 			regs[insn->dst_reg].type = CONST_IMM;
 			regs[insn->dst_reg].imm = insn->imm;
+			regs[insn->dst_reg].id = 0;
 			regs[insn->dst_reg].max_value = insn->imm;
 			regs[insn->dst_reg].min_value = insn->imm;
 			regs[insn->dst_reg].min_align = calc_align(insn->imm);
@@ -2565,6 +2566,7 @@ static int check_ld_imm(struct bpf_verif
 
 		regs[insn->dst_reg].type = CONST_IMM;
 		regs[insn->dst_reg].imm = imm;
+		regs[insn->dst_reg].id = 0;
 		return 0;
 	}