From patchwork Fri Feb 7 02:05:34 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peilin Ye X-Patchwork-Id: 13964224 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 C2FBF1487C8 for ; Fri, 7 Feb 2025 02:05:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738893941; cv=none; b=JZTkyU5VM5+4DDVPf7FHy+kNydmH/LshBFvH8Fb4Ul6/r+tD6/0QV2lWqHexmryoZGk6TCf/c15R3riZWCXtBLe6cWyJsAqH06BNlgy/RzqCqgXgGj+kIjW4HvNRHa9c8Wewgq47zNQoOaL0NwrXteQ6LfbljHWOdluWY7N4m+8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738893941; c=relaxed/simple; bh=Q2OkqnaEywltUrTvLR9BEhPUZfK5Xxof8YuvKLY13QU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=OCsosC9LnQTCN2Ftry/x2W9pJx398AmneDK7qZTqVc/ZW/9hUghpt1+xRjeOmtOHwAV2TkeTTJ0+sRi76fecpx47Y4qO531tWsX1OjIPkbRCyI9BlmAW5drkUzOROCEDxA00mEba8U/7z8xGjU9uaA7lA7eGVZ9Svxgs9gETzpw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--yepeilin.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=0F3zl6z7; arc=none smtp.client-ip=209.85.216.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--yepeilin.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="0F3zl6z7" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2fa11d8e448so3707609a91.0 for ; Thu, 06 Feb 2025 18:05:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738893939; x=1739498739; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=G0ksBymLsFxBv6dTHVXwRUMsPxued+iewutBsq02rrE=; b=0F3zl6z7IU/2gHkgczbWDC4O0lUQdtSX8LmnjIvSsPuLM+lgenSfRzqG5IubZFHFvj vryKzmdatssv9uKQoBPOOAsmHuy7fD3QYjZllwrgT7sc2EpHFvI8ZB37SNp26+roLzQQ JqLU832PLxNFQnc1n4epCQwbNU/3zzjUn97Scynro/NAmO+Pq9J+hdEM2ZISlqlU/C6d ivDk3nGqZceNc0nI4rcbOJyAy3itKisORrfLU3qM/WpfOpIE8zP7FCOpBdlhsVHeQKEc JSRQSZ4nmbWUNEHasmacdgM/UYAge9/ldrLkSUUG8bh45Yp4JPsa4oKhGdqdxgt2GPaT XPjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738893939; x=1739498739; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=G0ksBymLsFxBv6dTHVXwRUMsPxued+iewutBsq02rrE=; b=JixYGhmZXzqAetcv6F05yyI7eVwHxzXFFoAQMagL4GTR6c5et/FQlF3Eh+gGiwYM5v xgIT6to423T9TXGU8lDKBisn/PEQjs/EF3zX13j+Nkl5Nab0MKNA6Kbs/ZoUBVXd9Vnz QxiUJA4ecMSaCQN4urAI39hZ/K8D32C/cxF5gpsKgk2HwmdUyVYuYkVKkEiYl0zU3OVO TJV0f7Pi771AtZVc6XDZI0U+LH1mh79TlM77jLvokqSozOZ0H6aQnAwjGUsZI6rf59Qz ZB/PXfvVNtCpKq2vjuSszjd1ieVCtCDwk5+8Cx6E9pBkIMlWufUmO7E0OplFKxkIECdp cPeQ== X-Gm-Message-State: AOJu0YxrGjAJxNoet8C26Tt/Lnv3AlxId+L6UG9tT0ZFjWZ6xLGt71cy BI6sGPAZRNvAkRKKtng7+bVjmnz/0P/TCYqnelilInOv0mM8LZ2QWD/ae6iSxjh+Q3zkxMz0uh+ ZaCl9exZTiCFg4NlxgVS4145zrmHQsjVHse5MgbIkSbRWT8JSq6IqhwzjeWT52x0kPyKf79EeBJ sJyhOS8C21LO7+visUhs74/pFBdJw3h/FrhAu2LRE= X-Google-Smtp-Source: AGHT+IEQXS8/Za22ftZ1p+Phe57YwI7GpMBkpoOV+QxJBEcmY8iFZ5iWxAf92Zvu9JrzhNYd5itkmkXtR2L03w== X-Received: from pfai16.prod.google.com ([2002:aa7:9090:0:b0:72b:ccb:c99b]) (user=yepeilin job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:882:b0:71e:6b8:2f4a with SMTP id d2e1a72fcca58-7305d47c9d1mr2600297b3a.12.1738893938799; Thu, 06 Feb 2025 18:05:38 -0800 (PST) Date: Fri, 7 Feb 2025 02:05:34 +0000 In-Reply-To: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.48.1.502.g6dc24dfdaf-goog Message-ID: <363538659933fb2e289d937d81fc8eecb284ea7b.1738888641.git.yepeilin@google.com> Subject: [PATCH bpf-next v2 3/9] bpf/verifier: Factor out check_load_mem() and check_store_reg() From: Peilin Ye To: bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Peilin Ye , bpf@ietf.org, Xu Kuohai , Eduard Zingerman , David Vernet , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Jonathan Corbet , "Paul E. McKenney" , Puranjay Mohan , Ilya Leoshkevich , Heiko Carstens , Vasily Gorbik , Catalin Marinas , Will Deacon , Quentin Monnet , Mykola Lysenko , Shuah Khan , Ihor Solodrai , Yingchi Long , Josh Don , Barret Rhoden , Neel Natu , Benjamin Segall , linux-kernel@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Extract BPF_LDX and most non-atomic BPF_STX instruction handling logic in do_check() into helper functions to be used later. While we are here, make that comment about "reserved fields" more specific. Suggested-by: Eduard Zingerman Signed-off-by: Peilin Ye Acked-by: Eduard Zingerman --- kernel/bpf/verifier.c | 110 +++++++++++++++++++++++++----------------- 1 file changed, 67 insertions(+), 43 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 39eb990ec003..82a5a4acf576 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7536,6 +7536,67 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn static int save_aux_ptr_type(struct bpf_verifier_env *env, enum bpf_reg_type type, bool allow_trust_mismatch); +static int check_load_mem(struct bpf_verifier_env *env, struct bpf_insn *insn, + bool strict_alignment_once, bool is_ldsx, + bool allow_trust_mismatch, const char *ctx) +{ + struct bpf_reg_state *regs = cur_regs(env); + enum bpf_reg_type src_reg_type; + int err; + + /* check src operand */ + err = check_reg_arg(env, insn->src_reg, SRC_OP); + if (err) + return err; + + /* check dst operand */ + err = check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK); + if (err) + return err; + + src_reg_type = regs[insn->src_reg].type; + + /* Check if (src_reg + off) is readable. The state of dst_reg will be + * updated by this call. + */ + err = check_mem_access(env, env->insn_idx, insn->src_reg, insn->off, + BPF_SIZE(insn->code), BPF_READ, insn->dst_reg, + strict_alignment_once, is_ldsx); + err = err ?: save_aux_ptr_type(env, src_reg_type, + allow_trust_mismatch); + err = err ?: reg_bounds_sanity_check(env, ®s[insn->dst_reg], ctx); + + return err; +} + +static int check_store_reg(struct bpf_verifier_env *env, struct bpf_insn *insn, + bool strict_alignment_once) +{ + struct bpf_reg_state *regs = cur_regs(env); + enum bpf_reg_type dst_reg_type; + int err; + + /* check src1 operand */ + err = check_reg_arg(env, insn->src_reg, SRC_OP); + if (err) + return err; + + /* check src2 operand */ + err = check_reg_arg(env, insn->dst_reg, SRC_OP); + if (err) + return err; + + dst_reg_type = regs[insn->dst_reg].type; + + /* Check if (dst_reg + off) is writeable. */ + err = check_mem_access(env, env->insn_idx, insn->dst_reg, insn->off, + BPF_SIZE(insn->code), BPF_WRITE, insn->src_reg, + strict_alignment_once, false); + err = err ?: save_aux_ptr_type(env, dst_reg_type, false); + + return err; +} + static int check_atomic_rmw(struct bpf_verifier_env *env, struct bpf_insn *insn) { @@ -19051,35 +19112,16 @@ static int do_check(struct bpf_verifier_env *env) return err; } else if (class == BPF_LDX) { - enum bpf_reg_type src_reg_type; - - /* check for reserved fields is already done */ - - /* check src operand */ - err = check_reg_arg(env, insn->src_reg, SRC_OP); - if (err) - return err; + bool is_ldsx = BPF_MODE(insn->code) == BPF_MEMSX; - err = check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK); - if (err) - return err; - - src_reg_type = regs[insn->src_reg].type; - - /* check that memory (src_reg + off) is readable, - * the state of dst_reg will be updated by this func + /* Check for reserved fields is already done in + * resolve_pseudo_ldimm64(). */ - err = check_mem_access(env, env->insn_idx, insn->src_reg, - insn->off, BPF_SIZE(insn->code), - BPF_READ, insn->dst_reg, false, - BPF_MODE(insn->code) == BPF_MEMSX); - err = err ?: save_aux_ptr_type(env, src_reg_type, true); - err = err ?: reg_bounds_sanity_check(env, ®s[insn->dst_reg], "ldx"); + err = check_load_mem(env, insn, false, is_ldsx, true, + "ldx"); if (err) return err; } else if (class == BPF_STX) { - enum bpf_reg_type dst_reg_type; - if (BPF_MODE(insn->code) == BPF_ATOMIC) { err = check_atomic(env, insn); if (err) @@ -19093,25 +19135,7 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } - /* check src1 operand */ - err = check_reg_arg(env, insn->src_reg, SRC_OP); - if (err) - return err; - /* check src2 operand */ - err = check_reg_arg(env, insn->dst_reg, SRC_OP); - if (err) - return err; - - dst_reg_type = regs[insn->dst_reg].type; - - /* check that memory (dst_reg + off) is writeable */ - err = check_mem_access(env, env->insn_idx, insn->dst_reg, - insn->off, BPF_SIZE(insn->code), - BPF_WRITE, insn->src_reg, false, false); - if (err) - return err; - - err = save_aux_ptr_type(env, dst_reg_type, false); + err = check_store_reg(env, insn, false); if (err) return err; } else if (class == BPF_ST) {