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bpf: verifier: make kfuncs args nullalble

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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>
This commit is contained in:
Vadim Fedorenko 2024-06-13 14:18:13 -07:00 committed by Alexei Starovoitov
parent 373a4e13ab
commit a90797993a
1 changed files with 3 additions and 3 deletions
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6
kernel/bpf/verifier.c
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@ -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])))