From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo2-f38.google.com (mail-oo2-f38.google.com [74.125.231.166]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 36FC54F3934 for ; Fri, 25 Sep 2026 21:13:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.166 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790370795; cv=none; b=X3tWIoxPqKdJO47+wLWeFMMJuI3+cADoO0ml7KXa9RBKBYesvc4NBxgIaKQsvPlcSQHCs2ppvRVsPuEATcAPyMHIF7OP2DLlATLjRv39OFXzgmvCiDZgqfXe7LsDRI+P2/S9JyY8DqfvLOKJxlZUBb2m0qODhOXtQCgpns+vUv0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790370795; c=relaxed/simple; bh=xIXsxIzEXvYM4AcA9ZYwsww4LrojaMYOiP8jLU8zHn8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WK/T5wCY9XGXN7dmf6S6mv8J+mU91biC16xGefWqhz5XarEjPZb1Q1294CkuCfVMMLvym01IFrSqoKu3bUhi1qystzLjsQQxTR6dSxm6n+gQhgMMllJ5MGbv6VavRSD+U1zNvkgIHUusbfWXVzCXZ6v7IKB9Gb8skBWHtbPO+v0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=OPQp5Vab; arc=none smtp.client-ip=74.125.231.166 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OPQp5Vab" Received: by mail-oo2-f38.google.com with SMTP id 46e09a7af769-7f4f0cfb29cso706678a34.1 for ; Fri, 25 Sep 2026 14:13:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790370792; x=1790975592; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=o72FpJvOU7QXrfrkzZkMVkU3uzPWyWi1xbO17mwY7mM=; b=OPQp5Vab+/VwcwRw9LxZXY+MXYkrxIh+EjOqiqQL/3i1HMkWWt4mLM0e47kW1CGbxN JfC1W/D2rgHQztyOltaE/DQYIde7QTOL0ruZLwNgDeR4S18oVtsZWL8R5gwjmmdR4yyH G6KB/A7fs8+y1hFdp84hkpM4v/ZF3p2QlE9J4NjQLbSANpTpkKCrxsWwvqtCG6n8TpMH QHmReQWmwZSaU5r68o8+Mz1SeKjJbOkhlu5kVl8F+FJvqMwsLy8tRHUeTCRsBSX5ckGi CQZPeGk/GuoBUWb4hdzxcQb1cxkey9hrVgyKJNf7J0AkLMXm5GBafaKB8yn2LTrvyHq/ nCfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790370792; x=1790975592; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=o72FpJvOU7QXrfrkzZkMVkU3uzPWyWi1xbO17mwY7mM=; b=rylFaH+paPiipyP148pg3SwCfP7EuRKJnvRBP9eyS6x95LcIhYjrXQ4yQW9G9nLBw2 qY11LursgK4EfTU5Ll+70HtrDSS/uZ0L1N7gXOvuD8LO8Jv3SWBHyvZ7Xf/eRpQ3PlKz ack6etpQTRu51AczNrm84qfGEuFql7a+0+zGHAcWqUpkwxeOevVLDPFijumtxc036bj+ EVrydPlBmiReC5mUm+Nc8jMN0Xn+ROUFvjnb2PXn3yEQehWU42CTjR0ZwjFRXn6AuHod i/qDOpO6L7LH12iYFC3DNq3sCqO22WOKC2e1kWsdPn2E1tnW7uFxFQuTCvt9n9a2FOfB 2YOw== X-Gm-Message-State: AFuF++mfE8sMo4uK9z62HJNPxA8Vi1plIP/tUPGL1WNFi2a3Qf3M4bHe of724UR/mueAoB4671bkdRa1wUl+i453Ht+kKvJg7sBuII+M6i6ifcNCtOqhEA== X-Gm-Gg: AYBFou0LzozQb/swlYGuktmlDCsNMq53YiMaTcp/XRN2eavHj66XkRlPKLE/N4In/9L MjTpJ10Ky431EDH3G/dz3WOIDTKz5QZqyrfd2wDB26JzbNPNYXu2qQ6ewvJ3sT9Snu7NDrjMuoT 3I1kwicDqyOGIKBwRlLjZxlsKkRJYcnW2LBHl2iqKbGyv0nboUsbSoXFC2ASG14TfBY+7ficjp2 qsNs8zmI43td3iFsagJunBzZAs1xoAaFA+7ouQQ308UERFaAViyvFC6ndGPOM3zQACVZMc4L3kZ wCzF1FWUA+y4KLPK97F6QarLCW8t4fuFq7+jY2oMvR1pla9fm70xCerM5z5AtUqnxoXSKr6o8gB X0lgU0ZEJaUIM5ITDI/Z0k7jpfUv/H6hi1ITuq2O69ma2QOifw9oa1IWPF3/ybllpNu2hW2FXIJ 1VX/DESVoBFHAA6Zga21nxELUSj3KAxKLbl5FaJhNVXsuLt2zS8P1H4a9NE+/8usopz+XEWHHx X-Received: by 2002:a05:6830:4c03:b0:7f4:eaba:faf4 with SMTP id 46e09a7af769-81781489ca0mr9029629a34.11.1790370792371; Fri, 25 Sep 2026 14:13:12 -0700 (PDT) Received: from localhost ([2a03:2880:ff:14::]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-818e33f6714sm3370742a34.0.2026.09.25.14.13.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Sep 2026 14:13:10 -0700 (PDT) From: Amery Hung To: bpf@vger.kernel.org Cc: alexei.starovoitov@gmail.com, andrii@kernel.org, daniel@iogearbox.net, eddyz87@gmail.com, memxor@gmail.com, ameryhung@gmail.com, kernel-team@meta.com Subject: [PATCH bpf-next v1 09/12] bpf: Check global subprog BTF-ID arguments in the common path Date: Fri, 25 Sep 2026 14:12:53 -0700 Message-ID: <20260925211256.1834061-10-ameryhung@gmail.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260925211256.1834061-1-ameryhung@gmail.com> References: <20260925211256.1834061-1-ameryhung@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Route global ARG_PTR_TO_BTF_ID arguments through check_func_arg(). Use vmlinux BTF for their type match and retain the global-subprogram rules instead of applying kfunc-only trusted-pointer validation or runtime type resolution. The common nullability check now rejects non-nullable global BTF-ID arguments before register-type matching. Update the corresponding verifier log expectations. Signed-off-by: Amery Hung --- kernel/bpf/verifier.c | 31 +++++-------------- .../bpf/progs/verifier_global_ptr_args.c | 4 +-- 2 files changed, 10 insertions(+), 25 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 4a5c682ee73c..73a1c4877427 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -9512,7 +9512,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, u32 slot, u32 p case ARG_PTR_TO_BTF_ID_SOCK_COMMON: { const u32 *arg_btf_id = fn->arg_btf_id[arg]; - const struct btf *arg_btf = meta->btf ?: btf_vmlinux; + const struct btf *arg_btf = is_kfunc(meta) ? meta->btf : btf_vmlinux; if (!meta->btf) { const struct bpf_reg_types *compatible; @@ -9540,8 +9540,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, u32 slot, u32 p } } - if (meta->btf && (!is_trusted_reg(env, reg) || - bpf_type_has_unsafe_modifiers(reg->type))) { + if (is_kfunc(meta) && (!is_trusted_reg(env, reg) || + bpf_type_has_unsafe_modifiers(reg->type))) { if (!(arg_type & MEM_RCU)) { const char *actual_type, *arg_name, *expected_type; @@ -10817,6 +10817,8 @@ static void gen_subprog_arg_proto(const struct bpf_subprog_info *sub, const stru arg_type = ARG_IGNORE; } else if (base_type(arg_type) == ARG_PTR_TO_ARENA) { arg_type |= PTR_MAYBE_NULL; + } else if (base_type(arg_type) == ARG_PTR_TO_BTF_ID) { + proto->arg_btf_id[arg] = &sub->args[slot].btf_id; } proto->arg_type[arg] = arg_type; t = btf_type_skip_modifiers(btf, args[arg].type, NULL); @@ -10883,7 +10885,8 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog, if (arg_type == ARG_SCALAR || arg_type == ARG_IGNORE || arg_type == ARG_PTR_TO_CTX || arg_type == ARG_PTR_TO_DYNPTR || - base_type(arg_type) == ARG_PTR_TO_ARENA) { + base_type(arg_type) == ARG_PTR_TO_ARENA || + base_type(arg_type) == ARG_PTR_TO_BTF_ID) { ret = check_func_arg(env, arg, slot, 0, &meta, env->insn_idx); if (ret) return ret; @@ -10911,24 +10914,6 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog, reg_arg_name(env, argno)); return -EINVAL; } - } else if (base_type(arg_type) == ARG_PTR_TO_BTF_ID) { - int err; - - if (bpf_register_is_null(reg) && type_may_be_null(arg_type)) { - err = mark_arg_precision(env, argno); - if (err) - return err; - continue; - } - - err = check_reg_type(env, reg, argno, arg_type, &meta); - err = err ?: check_func_arg_reg_off(env, reg, argno, arg_type); - if (!err && base_type(reg->type) == PTR_TO_BTF_ID) - err = process_arg_ptr_to_btf_id(env, reg, argno, arg_type, - btf_vmlinux, sub->args[slot].btf_id, - &meta, env->insn_idx); - if (err) - return err; } else { verifier_bug(env, "unrecognized %s type %d", reg_arg_name(env, argno), arg_type); @@ -13073,7 +13058,7 @@ static int resolve_func_arg_type(struct bpf_verifier_env *env, if (base_type(*arg_type) != ARG_PTR_TO_BTF_ID) return 0; - if (!meta->btf || arg_type_is_release(*arg_type) || + if (!is_kfunc(meta) || arg_type_is_release(*arg_type) || base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)]) return 0; diff --git a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c index 10019af5eb74..f639e2767e35 100644 --- a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c +++ b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c @@ -87,7 +87,7 @@ __weak int subprog_trusted_task_nonnull(struct task_struct *task __arg_trusted) SEC("?kprobe") __failure __log_level(2) -__msg("R1 type=scalar expected=ptr_, trusted_ptr_, rcu_ptr_") +__msg("Possibly NULL pointer passed to trusted R1") __msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')") int trusted_task_arg_nonnull_fail1(void *ctx) { @@ -96,7 +96,7 @@ int trusted_task_arg_nonnull_fail1(void *ctx) SEC("?tp_btf/task_newtask") __failure __log_level(2) -__msg("R1 type=trusted_ptr_or_null_ expected=ptr_, trusted_ptr_, rcu_ptr_") +__msg("Possibly NULL pointer passed to trusted R1") __msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')") int trusted_task_arg_nonnull_fail2(void *ctx) { -- 2.52.0