From patchwork Thu Feb 20 01:20:55 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peilin Ye X-Patchwork-Id: 13983157 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (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 4496F146D53 for ; Thu, 20 Feb 2025 01:21:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740014466; cv=none; b=TMZ18DLO2sphfOt8xzCgY4j3WgOFvskjBk/kxxlSKAFHSYKVKZsgz/IMkbdNtoij9j4UDqP80b8F2fgQNALvYFzgM/nydhNY6ztQo5G5o+n2bmi2GN+mmvdVxudLDV/upa8SJeezUPfL1ofjyUr93KKML/pPf5tEU50OMOyKYJM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740014466; c=relaxed/simple; bh=gBOioH+MoGQo4UadYpQBkWbBwjDiFjFSK9/sF/gTzzc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=I6fcs2+XlVizPxaRlsqiTJNzBi/ZY7NS/P/j8pdnoI5UzDOuwKeWz4Elv1gizyPLQJHHjz4m+HHhvuJX6EyqsvTyfcNGbLz4S0y9aweB2SLjX11YrfbT8nOe8cmfw+Wh1lOvUFbtKVbMPiYBDwCGkwADCBEERWNdfRHL+QMBxGY= 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=o1Xr7c59; arc=none smtp.client-ip=209.85.214.201 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="o1Xr7c59" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-220fb031245so6605345ad.3 for ; Wed, 19 Feb 2025 17:21:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740014464; x=1740619264; 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=1aLixsgG5yYd8/b4s02+ROe3IhMkQne3dzUxBtDOXqk=; b=o1Xr7c59NceGMNLAgVB4e4fNi5hX8dE8QxDs937IMLekcRJ4Q4M7T7NfWirEJE/cVe k3gIax0JZymRtGJKgnk/K5Cf/udvtEEkfh0q6FKAZaLwyzmjqG/xuR5oqrkE03+NOTta 2k2gxjqVCb6FcdEGbM50fFtS6UZshaXD27mqNJZl5cxUpBhEeqK3aHbYXY49DsUVF90h EKlCfeVk+wL1Qw2uDmKt4mIrzDWflQuNzpuv9s+EIPt2+v+6o3YWILIqZajQKDku7H0k UcEtQ5WnIdSVXwfjxg/aQM3o1CYQoCpJyccoBsR6QOd9dQj5a1nl5L72QixcFnhdArsY U2fQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740014464; x=1740619264; 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=1aLixsgG5yYd8/b4s02+ROe3IhMkQne3dzUxBtDOXqk=; b=niM2VLKYoQVSsjMUSkERdaXZN0FhWzRhFxlzf/vvmB0BMoCfwZp4mqQsuWqnP2ZZgq VX5U/xhRXMDUUxteqjy9VD27pJey173+o6c9LQVRhGn9UKFybX4nWeHscITwGUNUzDnK C4vG40eLv8+72dAZIDNzheWURjUFNberccqjz+uFZpMK6Lmur/FFgR4SAuNZCFfWLWb3 ffMQNEvEMmfcsWDADX7CKJYn60MjHMgROPu9OhmTLXDgiVBmTjFiCZxaq7jtG6qFvclL IuHQ2lJPLKq7XN69VWvJfpnrzQSDd305JECGOgRWXekHgdoavhstEV98LhR72+ii1lqX DoWA== X-Gm-Message-State: AOJu0YxJYuZrOyWEQiceuD6r0TkWoxEg6+mwjf4gSv2uvM4kk0Yg20CO UZSpbUVAxYKDazAj/j90WflYr1r+blg2x0iuH00c8HteoZccxcHuLOYQB9WGqUkkQrSdaOboLtY VndE/3WFn25TqoBwPOt/HtOynKxDWZf9XYQ0viNCiAZo6QMWjUWZJMZYbY9e/U1OgAR0ajOZYie Yr5kFOKTolCSPXI8XMZYGZZc88k3kkxTklxiEqUJ4= X-Google-Smtp-Source: AGHT+IHUV95CcKWgBO0qp2SNUvCYSkhL2FrtNC7aRQZUoxAiCMv56jdPPY4vmUXwTTy3kWwJ9QOGDtLY3sIc/w== X-Received: from pgbfm14.prod.google.com ([2002:a05:6a02:498e:b0:ad5:4477:da5b]) (user=yepeilin job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:fc8f:b0:21a:8300:b9ce with SMTP id d9443c01a7336-221906a633cmr7766695ad.49.1740014464427; Wed, 19 Feb 2025 17:21:04 -0800 (PST) Date: Thu, 20 Feb 2025 01:20:55 +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 2.48.1.601.g30ceb7b040-goog Message-ID: <18f624573f4d5cb42ee877655ea0a96248447d7b.1740009184.git.yepeilin@google.com> Subject: [PATCH bpf-next v3 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 Acked-by: Eduard Zingerman Signed-off-by: Peilin Ye --- 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 63d810bbc26e..3b20bff1c5eb 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7615,6 +7615,67 @@ 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) { @@ -19162,35 +19223,16 @@ 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) @@ -19204,25 +19246,7 @@ 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) {