From: Vadim Fedorenko Date: Thu, 13 Jun 2024 21:18:13 +0000 (-0700) Subject: bpf: verifier: make kfuncs args nullalble X-Git-Tag: io_uring-6.11-20240722~71^2~68^2~60^2~4 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a90797993afcb0eaf6bf47a062ff47eb3810a6d5;p=linux-block.git 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 Signed-off-by: Vadim Fedorenko Link: https://lore.kernel.org/r/20240613211817.1551967-2-vadfed@meta.com Signed-off-by: Alexei Starovoitov --- 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], ®s[regno + 1]) || is_kfunc_arg_const_mem_size(meta->btf, &args[argno + 1], ®s[regno + 1])))