From nobody Sun Feb 8 18:43:12 2026 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 84D652940B for ; Fri, 7 Feb 2025 02:05:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738893941; cv=none; b=IZCUquqAklrWtrfo6NAPOusO21DzHJNWo1vKJoctvF8aZ5Zm7GDsrXsODvLizDccuLMSBNFUtTIeHcukJh/lopD2S2QaKqFds5jXptZFr4KfNFi/hUBViUw84VUAgQEQUGLOjRtrF1jpG948asDSGLsnKQgLaIciUjlUB56iTrA= 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=209.85.216.73 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-f73.google.com with SMTP id 98e67ed59e1d1-2fa1e63a5ffso2427608a91.3 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=Q7SkC0uar0GPfzkohw6ZovKK/WLDetwJS3uoa1AE6z08sbEzOE9tGiVmRYkKIK0iVT x91CfBWOV/IUWRwtXpn9zMhJ1yKR8n/XjrXKTpHDZGANuxVvE+QzsFnMfEwrq+VKNPjk pA3nznFSDzdXcU2KJo09KGRhzXqyye7XVsWlc0TXY68iL+7UBBlmG2ywWJ0UPtkjxtuR C9oWxkn5xoqJXZ65oD2eZGNFsG1ekKZ8pUawq17h+17z/FBpT3wC7bMSW+ihMXPIHIoy H/6IgZBc9xUGsbit7YiCYT85sTAAV1G+kx5ndzXmyl4w8LK+c86v60JKTjLF1r3ruG1r 64/g== X-Forwarded-Encrypted: i=1; AJvYcCXjm8WRphTZUf2/8MeCYdXKGNgvXcFpfG6/M1XDuoDb1y884bie1isiayFhIQB/kMpfFurvd3FmCz6tIfg=@vger.kernel.org X-Gm-Message-State: AOJu0YwkLKDHeEZ9/50gLI9Bzht+y0Bqr7jGqoIGv2tobzn7gVWpkbc0 xB83oAUewTt/9ihfKKmuzKSKG0DtHkhFWQIRqWM2Yx0D/C32oGRfqbImR9OUOXHnMgAaNc9ewbd piRyY1EGRAw== 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: linux-kernel@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 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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_ty= pe type, bool allow_trust_mismatch); =20 +static int check_load_mem(struct bpf_verifier_env *env, struct bpf_insn *i= nsn, + bool strict_alignment_once, bool is_ldsx, + bool allow_trust_mismatch, const char *ctx) +{ + struct bpf_reg_state *regs =3D cur_regs(env); + enum bpf_reg_type src_reg_type; + int err; + + /* check src operand */ + err =3D check_reg_arg(env, insn->src_reg, SRC_OP); + if (err) + return err; + + /* check dst operand */ + err =3D check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK); + if (err) + return err; + + src_reg_type =3D regs[insn->src_reg].type; + + /* Check if (src_reg + off) is readable. The state of dst_reg will be + * updated by this call. + */ + err =3D 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 =3D err ?: save_aux_ptr_type(env, src_reg_type, + allow_trust_mismatch); + err =3D 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 =3D cur_regs(env); + enum bpf_reg_type dst_reg_type; + int err; + + /* check src1 operand */ + err =3D check_reg_arg(env, insn->src_reg, SRC_OP); + if (err) + return err; + + /* check src2 operand */ + err =3D check_reg_arg(env, insn->dst_reg, SRC_OP); + if (err) + return err; + + dst_reg_type =3D regs[insn->dst_reg].type; + + /* Check if (dst_reg + off) is writeable. */ + err =3D 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 =3D 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; =20 } else if (class =3D=3D BPF_LDX) { - enum bpf_reg_type src_reg_type; - - /* check for reserved fields is already done */ - - /* check src operand */ - err =3D check_reg_arg(env, insn->src_reg, SRC_OP); - if (err) - return err; + bool is_ldsx =3D BPF_MODE(insn->code) =3D=3D BPF_MEMSX; =20 - err =3D check_reg_arg(env, insn->dst_reg, DST_OP_NO_MARK); - if (err) - return err; - - src_reg_type =3D 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 =3D 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) =3D=3D BPF_MEMSX); - err =3D err ?: save_aux_ptr_type(env, src_reg_type, true); - err =3D err ?: reg_bounds_sanity_check(env, ®s[insn->dst_reg], "ldx"= ); + err =3D check_load_mem(env, insn, false, is_ldsx, true, + "ldx"); if (err) return err; } else if (class =3D=3D BPF_STX) { - enum bpf_reg_type dst_reg_type; - if (BPF_MODE(insn->code) =3D=3D BPF_ATOMIC) { err =3D check_atomic(env, insn); if (err) @@ -19093,25 +19135,7 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } =20 - /* check src1 operand */ - err =3D check_reg_arg(env, insn->src_reg, SRC_OP); - if (err) - return err; - /* check src2 operand */ - err =3D check_reg_arg(env, insn->dst_reg, SRC_OP); - if (err) - return err; - - dst_reg_type =3D regs[insn->dst_reg].type; - - /* check that memory (dst_reg + off) is writeable */ - err =3D 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 =3D save_aux_ptr_type(env, dst_reg_type, false); + err =3D check_store_reg(env, insn, false); if (err) return err; } else if (class =3D=3D BPF_ST) { --=20 2.48.1.502.g6dc24dfdaf-goog