From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE12CC4743F for ; Tue, 8 Jun 2021 18:33:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9748613CC for ; Tue, 8 Jun 2021 18:33:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234512AbhFHSfq (ORCPT ); Tue, 8 Jun 2021 14:35:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:58040 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234700AbhFHSd7 (ORCPT ); Tue, 8 Jun 2021 14:33:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 46F6C613D5; Tue, 8 Jun 2021 18:31:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623177093; bh=xSZSnl7m2UGgysvLCU5ppFhx0YrUxXVXZlphh5Nb7fE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Upx8F3+eoSBGMYzCyru4w4rl+lE8Jf9JSNrWF+Qzi6i+XjEb2V7XKtVZh6fA/tS1V pw8fcLBWv65WS3icz7f7usAdKnhrKEDv1pCkBO6XwI/HVh/2awfAikt74sFWmtJmxS iKFHVH+PN546TXdNEuWCWcZ51oYVGzmTcl1u3gpg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Daniel Borkmann , John Fastabend , Alexei Starovoitov Subject: [PATCH 4.14 30/47] bpf: Rework ptr_limit into alu_limit and add common error path Date: Tue, 8 Jun 2021 20:27:13 +0200 Message-Id: <20210608175931.466685613@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210608175930.477274100@linuxfoundation.org> References: <20210608175930.477274100@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Daniel Borkmann commit b658bbb844e28f1862867f37e8ca11a8e2aa94a3 upstream. Small refactor with no semantic changes in order to consolidate the max ptr_limit boundary check. Signed-off-by: Daniel Borkmann Reviewed-by: John Fastabend Acked-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/verifier.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2026,12 +2026,12 @@ static struct bpf_insn_aux_data *cur_aux static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg, const struct bpf_reg_state *off_reg, - u32 *ptr_limit, u8 opcode) + u32 *alu_limit, u8 opcode) { bool off_is_neg = off_reg->smin_value < 0; bool mask_to_left = (opcode == BPF_ADD && off_is_neg) || (opcode == BPF_SUB && !off_is_neg); - u32 off, max; + u32 off, max = 0, ptr_limit = 0; if (!tnum_is_const(off_reg->var_off) && (off_reg->smin_value < 0) != (off_reg->smax_value < 0)) @@ -2045,22 +2045,27 @@ static int retrieve_ptr_limit(const stru max = MAX_BPF_STACK + mask_to_left; off = ptr_reg->off + ptr_reg->var_off.value; if (mask_to_left) - *ptr_limit = MAX_BPF_STACK + off; + ptr_limit = MAX_BPF_STACK + off; else - *ptr_limit = -off - 1; - return *ptr_limit >= max ? -ERANGE : 0; + ptr_limit = -off - 1; + break; case PTR_TO_MAP_VALUE: max = ptr_reg->map_ptr->value_size; if (mask_to_left) { - *ptr_limit = ptr_reg->umax_value + ptr_reg->off; + ptr_limit = ptr_reg->umax_value + ptr_reg->off; } else { off = ptr_reg->smin_value + ptr_reg->off; - *ptr_limit = ptr_reg->map_ptr->value_size - off - 1; + ptr_limit = ptr_reg->map_ptr->value_size - off - 1; } - return *ptr_limit >= max ? -ERANGE : 0; + break; default: return -EINVAL; } + + if (ptr_limit >= max) + return -ERANGE; + *alu_limit = ptr_limit; + return 0; } static bool can_skip_alu_sanitation(const struct bpf_verifier_env *env,