From a90797993afcb0eaf6bf47a062ff47eb3810a6d5 Mon Sep 17 00:00:00 2001 From: Vadim Fedorenko Date: Thu, 13 Jun 2024 14:18:13 -0700 Subject: 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 --- kernel/bpf/verifier.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') 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]))) -- cgit v1.2.3 From 65d6d61d25968d1f13a478a6f303ed8d6b978a77 Mon Sep 17 00:00:00 2001 From: Vadim Fedorenko Date: Thu, 13 Jun 2024 14:18:14 -0700 Subject: bpf: crypto: make state and IV dynptr nullable Some ciphers do not require state and IV buffer, but with current implementation 0-sized dynptr is always needed. With adjustment to verifier we can provide NULL instead of 0-sized dynptr. Make crypto kfuncs ready for this. Reviewed-by: Eduard Zingerman Signed-off-by: Vadim Fedorenko Link: https://lore.kernel.org/r/20240613211817.1551967-3-vadfed@meta.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/crypto.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/crypto.c b/kernel/bpf/crypto.c index 3c1de0e5c0bd..94854cd9c4cc 100644 --- a/kernel/bpf/crypto.c +++ b/kernel/bpf/crypto.c @@ -275,7 +275,7 @@ static int bpf_crypto_crypt(const struct bpf_crypto_ctx *ctx, if (__bpf_dynptr_is_rdonly(dst)) return -EINVAL; - siv_len = __bpf_dynptr_size(siv); + siv_len = siv ? __bpf_dynptr_size(siv) : 0; src_len = __bpf_dynptr_size(src); dst_len = __bpf_dynptr_size(dst); if (!src_len || !dst_len) @@ -303,42 +303,42 @@ static int bpf_crypto_crypt(const struct bpf_crypto_ctx *ctx, /** * bpf_crypto_decrypt() - Decrypt buffer using configured context and IV provided. - * @ctx: The crypto context being used. The ctx must be a trusted pointer. - * @src: bpf_dynptr to the encrypted data. Must be a trusted pointer. - * @dst: bpf_dynptr to the buffer where to store the result. Must be a trusted pointer. - * @siv: bpf_dynptr to IV data and state data to be used by decryptor. + * @ctx: The crypto context being used. The ctx must be a trusted pointer. + * @src: bpf_dynptr to the encrypted data. Must be a trusted pointer. + * @dst: bpf_dynptr to the buffer where to store the result. Must be a trusted pointer. + * @siv__nullable: bpf_dynptr to IV data and state data to be used by decryptor. May be NULL. * * Decrypts provided buffer using IV data and the crypto context. Crypto context must be configured. */ __bpf_kfunc int bpf_crypto_decrypt(struct bpf_crypto_ctx *ctx, const struct bpf_dynptr *src, const struct bpf_dynptr *dst, - const struct bpf_dynptr *siv) + const struct bpf_dynptr *siv__nullable) { const struct bpf_dynptr_kern *src_kern = (struct bpf_dynptr_kern *)src; const struct bpf_dynptr_kern *dst_kern = (struct bpf_dynptr_kern *)dst; - const struct bpf_dynptr_kern *siv_kern = (struct bpf_dynptr_kern *)siv; + const struct bpf_dynptr_kern *siv_kern = (struct bpf_dynptr_kern *)siv__nullable; return bpf_crypto_crypt(ctx, src_kern, dst_kern, siv_kern, true); } /** * bpf_crypto_encrypt() - Encrypt buffer using configured context and IV provided. - * @ctx: The crypto context being used. The ctx must be a trusted pointer. - * @src: bpf_dynptr to the plain data. Must be a trusted pointer. - * @dst: bpf_dynptr to buffer where to store the result. Must be a trusted pointer. - * @siv: bpf_dynptr to IV data and state data to be used by decryptor. + * @ctx: The crypto context being used. The ctx must be a trusted pointer. + * @src: bpf_dynptr to the plain data. Must be a trusted pointer. + * @dst: bpf_dynptr to the buffer where to store the result. Must be a trusted pointer. + * @siv__nullable: bpf_dynptr to IV data and state data to be used by decryptor. May be NULL. * * Encrypts provided buffer using IV data and the crypto context. Crypto context must be configured. */ __bpf_kfunc int bpf_crypto_encrypt(struct bpf_crypto_ctx *ctx, const struct bpf_dynptr *src, const struct bpf_dynptr *dst, - const struct bpf_dynptr *siv) + const struct bpf_dynptr *siv__nullable) { const struct bpf_dynptr_kern *src_kern = (struct bpf_dynptr_kern *)src; const struct bpf_dynptr_kern *dst_kern = (struct bpf_dynptr_kern *)dst; - const struct bpf_dynptr_kern *siv_kern = (struct bpf_dynptr_kern *)siv; + const struct bpf_dynptr_kern *siv_kern = (struct bpf_dynptr_kern *)siv__nullable; return bpf_crypto_crypt(ctx, src_kern, dst_kern, siv_kern, false); } -- cgit v1.2.3