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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 E4FD2C4360F for ; Mon, 25 Feb 2019 21:24:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B344F217F9 for ; Mon, 25 Feb 2019 21:24:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551129844; bh=uVnLJcgyMe0peK9Ivx6BGEap0aoatFMeCz3d58fiCys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sOdpobvWTMPyP3LhQmYQnztCqr3tvActn/UMtt1NJjMx8gs/uySNbv4UoJRWYz2AB 64XrDAe57Eiifm74abUWX17x2n3qgK3QmjIrx9jZj1YDXqhD6C0ZtUXAZdbX7n9459 Y6o7e1ERaUUQpRTMu3lQrFWyKuuD/eA63p/V5iu8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731193AbfBYVYD (ORCPT ); Mon, 25 Feb 2019 16:24:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:58506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730793AbfBYVYB (ORCPT ); Mon, 25 Feb 2019 16:24:01 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A3743213A2; Mon, 25 Feb 2019 21:24:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551129841; bh=uVnLJcgyMe0peK9Ivx6BGEap0aoatFMeCz3d58fiCys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EmQ2xfihNwcmFlsVGTgUU9b9hYx+vXbZxz3KQzqsPKOJ9esysC7Y9fFYf8TofX432 Ipivl8lP69SrxU2cZjgDPAji5DblSqPnFI98Pe3pQPswnh8gpbA/nfBFkFD8P4nSRH Bag//XGL0iOBOCyBO0loxBhAA8DqoLTn7j3wNzK8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Song Liu , Stanislav Fomichev , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.19 084/152] bpf: dont assume build-id length is always 20 bytes Date: Mon, 25 Feb 2019 22:11:16 +0100 Message-Id: <20190225195048.842540274@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190225195043.645958524@linuxfoundation.org> References: <20190225195043.645958524@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 0b698005a9d11c0e91141ec11a2c4918a129f703 ] Build-id length is not fixed to 20, it can be (`man ld` /--build-id): * 128-bit (uuid) * 160-bit (sha1) * any length specified in ld --build-id=0xhexstring To fix the issue of missing BPF_STACK_BUILD_ID_VALID for shorter build-ids, assume that build-id is somewhere in the range of 1 .. 20. Set the remaining bytes to zero. v2: * don't introduce new "len = min(BPF_BUILD_ID_SIZE, nhdr->n_descsz)", we already know that nhdr->n_descsz <= BPF_BUILD_ID_SIZE if we enter this 'if' condition Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Acked-by: Song Liu Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- kernel/bpf/stackmap.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index e50ef5bca4213..98ad9dc3587aa 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -180,11 +180,14 @@ static inline int stack_map_parse_build_id(void *page_addr, if (nhdr->n_type == BPF_BUILD_ID && nhdr->n_namesz == sizeof("GNU") && - nhdr->n_descsz == BPF_BUILD_ID_SIZE) { + nhdr->n_descsz > 0 && + nhdr->n_descsz <= BPF_BUILD_ID_SIZE) { memcpy(build_id, note_start + note_offs + ALIGN(sizeof("GNU"), 4) + sizeof(Elf32_Nhdr), - BPF_BUILD_ID_SIZE); + nhdr->n_descsz); + memset(build_id + nhdr->n_descsz, 0, + BPF_BUILD_ID_SIZE - nhdr->n_descsz); return 0; } new_offs = note_offs + sizeof(Elf32_Nhdr) + -- 2.19.1