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: 13964235 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AB0BDC02194 for ; Fri, 7 Feb 2025 02:10:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=G0ksBymLsFxBv6dTHVXwRUMsPxued+iewutBsq02rrE=; b=QzKpgmj6wsceqv856vlo+vztFy d+gsX6W/AVpvPf18Ij0m6iyaRxqiKSoE1AZov2ovhSa77oX6C5v3adIQrIjNEoGVtqzWir3+cLu6h ZQiVAYTGSh5mtmoDRt1qGVor2+aWgLqugNEXYdTbQKZ1ZeEwFX1fQ8r7Jlsb3pa65LnqsX61QjGvc gvxJvet8dwqrs/fECk6BIkOaef9XhQeu47HaL+H/1jBHMQNc19p1fCoC17F5DOhCVBuWqvT/XOmb2 9XOoTmQQ+7TrZH3rWV8/7epWPxt/tcjKtqocuYaJQN1gKLowWeyAL1tHYt3i1wugnekRyDBU+bqKX yUY10g3Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tgDpH-000000082Kc-2JTG; Fri, 07 Feb 2025 02:10:39 +0000 Received: from mail-pj1-x1049.google.com ([2607:f8b0:4864:20::1049]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tgDkR-000000081Rj-3ldS for linux-arm-kernel@lists.infradead.org; Fri, 07 Feb 2025 02:05:41 +0000 Received: by mail-pj1-x1049.google.com with SMTP id 98e67ed59e1d1-2f9e1bf0a3bso5200591a91.2 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=lists.infradead.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=VSjsMtZe0PaXh/kIHI/4+26ehWi/OWT1f/AZWHXqPgHE7JLiWsXCycxyfavWqxqmqS BzklfnvxWDHYQR3Y7TOHBGDVBoewthGm+1qIfW5poke0QWf5LTk//Dc2H32VKcQ/zA32 IXH0Bqzv7olpRPt84I72dtr6pga6CI1YNcUC6QSs91XKczurZyow5OzBXASzkgcWUSbj ucDAn+vZ6y/r9DLqZTW5kdS7CKcl3mMy+s978infRYQ9sDe3v+mA2ab6z2KTOcE7473S 8sWsWc1jo88FQk3okvEM6mES1gvhZb7S5Jz/RodeKqPVLG+lIeHUNQL76pYBqqXZHD6a kArA== 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=HUzjNwwXjE8ZnQl2kCtbjx3ZW11xGp1HVhD0g3I986SHw3cLIaJEsLLWk97iOFRL+Q aid4RpgFi/tfK1t0nKQn8qLwmiz9gakUGUHUD4V6tpf2X1xJK0Gfc7xRB/g5jT4DeNaH JkvKL5drCRFatDEyHSQ8YFX9MvSFnvm68uKYUMTapkKZ2uSh1JFd8Ohp+rUVQsJ6Un7h nInjW7oErrkgW2zIjT3/vPipPaGzc60P4zwK+ImUbSnILMbu6tOTi327o6cKjSsclItY S78mmgT6hTbu/ltR9Dfo4QCF0B37btWR9wUlPKju77ue8PfBXgtOfvP5jLnvK9V3TKmv vuCw== X-Forwarded-Encrypted: i=1; AJvYcCXB6Mhd9OpUzzQoucBlQ/+RWrc8W/clCgfvheGnegt0mBfenzmLpAAQBqL+hICJjj1A+kNDedlbQQBTgy1kHjpK@lists.infradead.org X-Gm-Message-State: AOJu0YwYg1TfJfAFCavRWFiqdna8kILkBWDBI+ugQWMz1zg5w1Hdb1y2 KKFLLmlzDrQuxcmz9BscoB3FNInj6+AZLB0aiQnYicMqDAvkzi0EixcGOHO6XNLGIY94awhsPkP TA2hl1fpOKg== 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: 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250206_180539_938378_E13DB57C X-CRM114-Status: GOOD ( 16.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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) {