1 files changed, 20 insertions, 8 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d28f9a3380a9..83ed2f8f6f22 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -462,14 +462,19 @@ static void init_reg_state(struct bpf_reg_state *regs)
 	regs[BPF_REG_1].type = PTR_TO_CTX;
 }
 
-static void mark_reg_unknown_value(struct bpf_reg_state *regs, u32 regno)
+static void __mark_reg_unknown_value(struct bpf_reg_state *regs, u32 regno)
 {
-	BUG_ON(regno >= MAX_BPF_REG);
 	regs[regno].type = UNKNOWN_VALUE;
 	regs[regno].id = 0;
 	regs[regno].imm = 0;
 }
 
+static void mark_reg_unknown_value(struct bpf_reg_state *regs, u32 regno)
+{
+	BUG_ON(regno >= MAX_BPF_REG);
+	__mark_reg_unknown_value(regs, regno);
+}
+
 static void reset_reg_range_values(struct bpf_reg_state *regs, u32 regno)
 {
 	regs[regno].min_value = BPF_REGISTER_MIN_RANGE;
@@ -1970,8 +1975,13 @@ static void mark_map_reg(struct bpf_reg_state *regs, u32 regno, u32 id,
 
 	if (reg->type == PTR_TO_MAP_VALUE_OR_NULL && reg->id == id) {
 		reg->type = type;
+		/* We don't need id from this point onwards anymore, thus we
+		 * should better reset it, so that state pruning has chances
+		 * to take effect.
+		 */
+		reg->id = 0;
 		if (type == UNKNOWN_VALUE)
-			mark_reg_unknown_value(regs, regno);
+			__mark_reg_unknown_value(regs, regno);
 	}
 }
 
@@ -1982,16 +1992,16 @@ static void mark_map_regs(struct bpf_verifier_state *state, u32 regno,
 			  enum bpf_reg_type type)
 {
 	struct bpf_reg_state *regs = state->regs;
+	u32 id = regs[regno].id;
 	int i;
 
 	for (i = 0; i < MAX_BPF_REG; i++)
-		mark_map_reg(regs, i, regs[regno].id, type);
+		mark_map_reg(regs, i, id, type);
 
 	for (i = 0; i < MAX_BPF_STACK; i += BPF_REG_SIZE) {
 		if (state->stack_slot_type[i] != STACK_SPILL)
 			continue;
-		mark_map_reg(state->spilled_regs, i / BPF_REG_SIZE,
-			     regs[regno].id, type);
+		mark_map_reg(state->spilled_regs, i / BPF_REG_SIZE, id, type);
 	}
 }
 
@@ -2926,6 +2936,10 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
 	int insn_cnt = env->prog->len;
 	int i, j, err;
 
+	err = bpf_prog_calc_digest(env->prog);
+	if (err)
+		return err;
+
 	for (i = 0; i < insn_cnt; i++, insn++) {
 		if (BPF_CLASS(insn->code) == BPF_LDX &&
 		    (BPF_MODE(insn->code) != BPF_MEM || insn->imm != 0)) {
@@ -3173,8 +3187,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
 		log_level = 0;
 	}
 
-	bpf_prog_calc_digest(env->prog);
-
 	ret = replace_map_fd_with_map_ptr(env);
 	if (ret < 0)
 		goto skip_full_check;