From: Stanislav Fomichev <[email protected]>

commit e4f07120210a1794c1f1ae64d209a2fbc7bd2682 upstream.

Commit 1dc92851849c ("bpf: kernel side support for BTF Var and DataSec")
added invocations of btf_type_is_resolve_source_only before
btf_type_nosize_or_null which checks for the NULL pointer.
Swap the order of btf_type_nosize_or_null and
btf_type_is_resolve_source_only to make sure the do the NULL pointer
check first.

Fixes: 1dc92851849c ("bpf: kernel side support for BTF Var and DataSec")
Reported-by: syzbot <[email protected]>
Signed-off-by: Stanislav Fomichev <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 kernel/bpf/btf.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -1928,8 +1928,8 @@ static int btf_array_resolve(struct btf_
        /* Check array->index_type */
        index_type_id = array->index_type;
        index_type = btf_type_by_id(btf, index_type_id);
-       if (btf_type_is_resolve_source_only(index_type) ||
-           btf_type_nosize_or_null(index_type)) {
+       if (btf_type_nosize_or_null(index_type) ||
+           btf_type_is_resolve_source_only(index_type)) {
                btf_verifier_log_type(env, v->t, "Invalid index");
                return -EINVAL;
        }
@@ -1948,8 +1948,8 @@ static int btf_array_resolve(struct btf_
        /* Check array->type */
        elem_type_id = array->type;
        elem_type = btf_type_by_id(btf, elem_type_id);
-       if (btf_type_is_resolve_source_only(elem_type) ||
-           btf_type_nosize_or_null(elem_type)) {
+       if (btf_type_nosize_or_null(elem_type) ||
+           btf_type_is_resolve_source_only(elem_type)) {
                btf_verifier_log_type(env, v->t,
                                      "Invalid elem");
                return -EINVAL;
@@ -2170,8 +2170,8 @@ static int btf_struct_resolve(struct btf
                const struct btf_type *member_type = btf_type_by_id(env->btf,
                                                                member_type_id);
 
-               if (btf_type_is_resolve_source_only(member_type) ||
-                   btf_type_nosize_or_null(member_type)) {
+               if (btf_type_nosize_or_null(member_type) ||
+                   btf_type_is_resolve_source_only(member_type)) {
                        btf_verifier_log_member(env, v->t, member,
                                                "Invalid member");
                        return -EINVAL;


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