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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 086CCC282C4 for ; Wed, 13 Feb 2019 02:51:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C26F721934 for ; Wed, 13 Feb 2019 02:51:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550026289; bh=GQAXvw6KG/MbUQKVUkJyUMA2iGV2/OLdQ/9/ZE1cO98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jPxEPWvCV6RQ3U46BD/Lj3o37vCmVUHlSejq+O9TmHm5L7QryC63JiFDrCEThLkKT TdJ261l7og0neZzukRXWRsykPXt2RAbasrbkYBRhtCva1eLwjwb6I1CrVnkEHkbRnz MuntANeKU7OBOfEl19TndCjoo6dV2BJKDkLdy6oQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389828AbfBMCv3 (ORCPT ); Tue, 12 Feb 2019 21:51:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:42964 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388681AbfBMCjY (ORCPT ); Tue, 12 Feb 2019 21:39:24 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2CDBD222C7; Wed, 13 Feb 2019 02:39:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025563; bh=GQAXvw6KG/MbUQKVUkJyUMA2iGV2/OLdQ/9/ZE1cO98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bKp/Z0PRNKZA3MXt3x7ZQHd6EcazAgatkGFdobgAwhl7eYgdgoA08CNFdhxuhnlmN nSrp5kbLWGDf875bDx0RFDtWAv870++FRZnfKsUFti5sdRQ1eSqV8nwwgtP0vP+tmP c+SdM4cHt9MItCDYR1tjO42/mfteTnaUU1BlV4vY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Stanislav Fomichev , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 70/83] bpf: don't assume build-id length is always 20 bytes Date: Tue, 12 Feb 2019 21:36:48 -0500 Message-Id: <20190213023701.20286-70-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190213023701.20286-1-sashal@kernel.org> References: <20190213023701.20286-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Stanislav Fomichev [ 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 e50ef5bca421..98ad9dc3587a 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