From patchwork Fri Aug 13 15:07:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 12435721 X-Patchwork-Delegate: bpf@iogearbox.net 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=-19.4 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 8C5F4C4320A for ; Fri, 13 Aug 2021 15:14:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 710A46112E for ; Fri, 13 Aug 2021 15:14:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241321AbhHMPOF (ORCPT ); Fri, 13 Aug 2021 11:14:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:57162 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241951AbhHMPNB (ORCPT ); Fri, 13 Aug 2021 11:13:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A8C966112D; Fri, 13 Aug 2021 15:12:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628867554; bh=r/It5R4/yhQY6rvDBmpY0DcKcwXQ2ZWlt5AclDMwB+w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T8Uid0oLC0ezrRrlNdzllD1geSCeTQbNFgVvjHrTFnuAkhM+xIoXXwes5ECfM3jUr pptTCv91BX0rgbNuIC3J+y0nfM+WhkN4uHotrnrEf7RbU/g7PnC3fxn+NyuAa5IcVk Uh0EM8+j/vVWw6gWVtqpEnQyZmxty24FLVt2YEeA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , bpf@vger.kernel.org, Daniel Borkmann , John Fastabend , Benedict Schlueter , Piotr Krysiuk , Alexei Starovoitov , Ovidiu Panait Subject: [PATCH 4.19 03/11] bpf: Inherit expanded/patched seen count from old aux data Date: Fri, 13 Aug 2021 17:07:10 +0200 Message-Id: <20210813150520.181696817@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210813150520.072304554@linuxfoundation.org> References: <20210813150520.072304554@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Daniel Borkmann commit d203b0fd863a2261e5d00b97f3d060c4c2a6db71 upstream. Instead of relying on current env->pass_cnt, use the seen count from the old aux data in adjust_insn_aux_data(), and expand it to the new range of patched instructions. This change is valid given we always expand 1:n with n>=1, so what applies to the old/original instruction needs to apply for the replacement as well. Not relying on env->pass_cnt is a prerequisite for a later change where we want to avoid marking an instruction seen when verified under speculative execution path. Signed-off-by: Daniel Borkmann Reviewed-by: John Fastabend Reviewed-by: Benedict Schlueter Reviewed-by: Piotr Krysiuk Acked-by: Alexei Starovoitov [OP: - declare old_data as bool instead of u32 (struct bpf_insn_aux_data.seen is bool in 5.4) - adjusted context for 4.19] Signed-off-by: Ovidiu Panait Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/verifier.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5690,6 +5690,7 @@ static int adjust_insn_aux_data(struct b u32 off, u32 cnt) { struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; + bool old_seen = old_data[off].seen; int i; if (cnt == 1) @@ -5701,8 +5702,10 @@ static int adjust_insn_aux_data(struct b memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off); memcpy(new_data + off + cnt - 1, old_data + off, sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1)); - for (i = off; i < off + cnt - 1; i++) - new_data[i].seen = true; + for (i = off; i < off + cnt - 1; i++) { + /* Expand insni[off]'s seen count to the patched range. */ + new_data[i].seen = old_seen; + } env->insn_aux_data = new_data; vfree(old_data); return 0;