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authorVadim Fedorenko <vadfed@meta.com>2024-06-13 14:18:13 -0700
committerAlexei Starovoitov <ast@kernel.org>2024-06-13 16:33:04 -0700
commita90797993afcb0eaf6bf47a062ff47eb3810a6d5 (patch)
treebae52ca95911eef3ebeb75bfa1c4d261737a3c2d
parent373a4e13ab4bc947f429fd92409d686fbec57132 (diff)
bpf: verifier: make kfuncs args nullalble
Some arguments to kfuncs might be NULL in some cases. But currently it's not possible to pass NULL to any BTF structures because the check for the suffix is located after all type checks. Move it to earlier place to allow nullable args. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Vadim Fedorenko <vadfed@meta.com> Link: https://lore.kernel.org/r/20240613211817.1551967-2-vadfed@meta.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--kernel/bpf/verifier.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index acc9dd830807..e857b08e1f2d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11187,6 +11187,9 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env,
if (btf_is_prog_ctx_type(&env->log, meta->btf, t, resolve_prog_type(env->prog), argno))
return KF_ARG_PTR_TO_CTX;
+ if (is_kfunc_arg_nullable(meta->btf, &args[argno]) && register_is_null(reg))
+ return KF_ARG_PTR_TO_NULL;
+
if (is_kfunc_arg_alloc_obj(meta->btf, &args[argno]))
return KF_ARG_PTR_TO_ALLOC_BTF_ID;
@@ -11232,9 +11235,6 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env,
if (is_kfunc_arg_callback(env, meta->btf, &args[argno]))
return KF_ARG_PTR_TO_CALLBACK;
- if (is_kfunc_arg_nullable(meta->btf, &args[argno]) && register_is_null(reg))
- return KF_ARG_PTR_TO_NULL;
-
if (argno + 1 < nargs &&
(is_kfunc_arg_mem_size(meta->btf, &args[argno + 1], &regs[regno + 1]) ||
is_kfunc_arg_const_mem_size(meta->btf, &args[argno + 1], &regs[regno + 1])))