[PATCH bpf-next v3 06/14] bpf: Move BPF_STX reserved field check into BPF_STX verifier code

From: Brendan Jackman
Date: Thu Dec 03 2020 - 11:05:10 EST


I can't find a reason why this code is in resolve_pseudo_ldimm64;
since I'll be modifying it in a subsequent commit, tidy it up.

Change-Id: I3410469270f4889a3af67612bd6c2e7979ab4da1
Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
---
kernel/bpf/verifier.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1947da617b03..e8b41ccdfb90 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -9501,6 +9501,12 @@ static int do_check(struct bpf_verifier_env *env)
} else if (class == BPF_STX) {
enum bpf_reg_type *prev_dst_type, dst_reg_type;

+ if (((BPF_MODE(insn->code) != BPF_MEM &&
+ BPF_MODE(insn->code) != BPF_ATOMIC) || insn->imm != 0)) {
+ verbose(env, "BPF_STX uses reserved fields\n");
+ return -EINVAL;
+ }
+
if (BPF_MODE(insn->code) == BPF_ATOMIC) {
err = check_atomic(env, env->insn_idx, insn);
if (err)
@@ -9910,13 +9916,6 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
return -EINVAL;
}

- if (BPF_CLASS(insn->code) == BPF_STX &&
- ((BPF_MODE(insn->code) != BPF_MEM &&
- BPF_MODE(insn->code) != BPF_ATOMIC) || insn->imm != 0)) {
- verbose(env, "BPF_STX uses reserved fields\n");
- return -EINVAL;
- }
-
if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW)) {
struct bpf_insn_aux_data *aux;
struct bpf_map *map;
--
2.29.2.454.gaff20da3a2-goog