From patchwork Mon Mar 3 05:37:25 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peilin Ye X-Patchwork-Id: 13998211 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 063FE1E4110 for ; Mon, 3 Mar 2025 05:37:30 +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=1740980252; cv=none; b=fbWEnab4+JlBmYYClKWFFtXhoIxpd2W9ZP64yF3f1Bug2w1LMoqRg43vWSWPlPJJygLwZSJXc0BTectsUZuowO/tRYUBWoOvGbdbRwocA+QwKQYisuQM4mbUCh8ME5H/epaOo+E3k2XGeB07MXZD3T0epDUrWIkU9KW+hk/VhF4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740980252; c=relaxed/simple; bh=2pUxXz0akFFxs2mApNxz+YR/0wzJxt2EpT0EmaU7eKw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=fbLVHf6eJBjPzrvYe8liZTqHeIcYLn6bVw4FoiBabOdhsuKm9qXqF/AInw9vGdMI9pVxNoABl3Pv3DqJUuR9lAw/YraG8WxVMlb5JUF+pTg6S7Guc5VX9ehgGQEsHMpyIMAsgTFAPrgO+TgMp8nq745eKRvbGGplKu5Gkl0naBk= 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=rXOcv6a2; 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="rXOcv6a2" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-22328fb6cbfso72619925ad.2 for ; Sun, 02 Mar 2025 21:37:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740980250; x=1741585050; 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=xPM/d8ucU/aCvkPtTtqBYkvS0mdPeqTCnB8f7vkTZfc=; b=rXOcv6a2j/dOy5VcjbbrIjoM8Exp0gbzIPHFN6YZ0egQZDNjJdIQRLxtNXH/u2KehL bNdvvnOswMwdgWHDybfTuEqwO3XCkWv/kzOy09UONGSIG/gg7jTElp9dFKGXDRw5uYJR 0zLuGun4/evLyPM47ICKAnohoIv8yd5XbqfRxHusBQmcQmIfLizp0MEyGKFU5H7u0qVE /wHL06xHsk/AMDu5BileIcikr6runlBHtrjMYBkAoyo50Qa7G23TMxbWrnZP/gzqbrcD UZiy3tfhclQqY5a4BneNAVGaZJ42ax2I6k3nQ+ysCuoWjD+rjVNnM77e4Lvs7jTvsn/G yVWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740980250; x=1741585050; 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=xPM/d8ucU/aCvkPtTtqBYkvS0mdPeqTCnB8f7vkTZfc=; b=d+mApXEMODkcL44nygs3WxCWtEjr7egBfi44VjcF5p0Zk+6S240kpsa8j8ZWPx4Pxe NGSI/FTlnmWwa5CbPEQ7IyE/Hbo6B0Y91m3tG4sRUI8WHjB5Y8dMZOyz0FnELqm65AMm uc/YSRUGWadpJdY3eaLro1OXuWiTLJJkxEL+IxVSxB7jdQmQCjRE97jctN7Jb0B4IncI NdxIfr8h+PSZuapNrXxf1AvxKWsbkPqQxGGZws3ZL5vb2O2SATU0aIvyP5RRDtUqv80t a7d4+udD54M4am5Ixi9Uy4VNou2kPH12fIv+eH5VrpU+LhaHbb9m5e9DoihHy3KKHZhF df4Q== X-Gm-Message-State: AOJu0Yxw+P72BLCDNO8CgZBR0bWiSWJUtKe1G4SjlJ0QSiRe49YQpxDg 0LNj9gN/+kyhK4zIDXsYxKYAaEyoJGnNZ7s1aMrY7TyXb/Qxm2hNUTVOx4T9+ce3LNxVGIlcjM7 ZC49hFH1EgpMPOke9OcJW1dDHFJnkO3a6RXm1WhyqP4iN0Iq/zZpeohVO/eLtdtQ+N8Kym6WUsp WLyNx7S2q7MHOJEfstzlS06aPRIFxYOymUu2AdqUg= X-Google-Smtp-Source: AGHT+IFd0bRzT6Rf6GCL8yvgeLbmofEZHIi8D+gz8MXJG3yNYxhrfMMp8T7aKzxnwK4iYpxZh2FJ3rZewRiYoA== X-Received: from pjur6.prod.google.com ([2002:a17:90a:d406:b0:2fc:2959:b397]) (user=yepeilin job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:244d:b0:216:6901:d588 with SMTP id d9443c01a7336-22368f75980mr157873115ad.15.1740980250225; Sun, 02 Mar 2025 21:37:30 -0800 (PST) Date: Mon, 3 Mar 2025 05:37:25 +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 2.48.1.711.g2feabab25a-goog Message-ID: <8b39c94eac2bb7389ff12392ca666f939124ec4f.1740978603.git.yepeilin@google.com> Subject: [PATCH bpf-next v4 03/10] 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, Alexei Starovoitov , Xu Kuohai , Eduard Zingerman , David Vernet , 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 e3991ac72029..22c4edc8695c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7616,6 +7616,67 @@ 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) { @@ -19199,35 +19260,16 @@ 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) @@ -19241,25 +19283,7 @@ 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) {