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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D2D1C433F5 for ; Mon, 15 Nov 2021 23:03:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53F3E6109E for ; Mon, 15 Nov 2021 23:03:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244531AbhKOXGU (ORCPT ); Mon, 15 Nov 2021 18:06:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:59672 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243485AbhKOS7x (ORCPT ); Mon, 15 Nov 2021 13:59:53 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6B484611F0; Mon, 15 Nov 2021 18:13:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637000005; bh=g/bilKBDC6h29mvOMbtjEL+7rCtNxHcGMr1IWUxpL+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mSnEUWf5hbLtUCIWGQuhpMk0E1KQVFyC7X0uGIwMQLkA7X8pU/sMSPqrwld/S2JAO vmd6PGftBEs75S26OPH3TtG4c+N1nA4r0CrPOIWKSSEP+RztB/CLQyUm7CkcXuAtfo rf379E1eqHRD4yhnoJ4sWideUBiwNzwacOCieGjM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Evgeny Vereshchagin , Andrii Nakryiko , Alexei Starovoitov , Sasha Levin Subject: [PATCH 5.14 495/849] libbpf: Fix BTF header parsing checks Date: Mon, 15 Nov 2021 17:59:38 +0100 Message-Id: <20211115165437.032830792@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165419.961798833@linuxfoundation.org> References: <20211115165419.961798833@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: linux-kernel@vger.kernel.org From: Andrii Nakryiko [ Upstream commit c825f5fee19caf301d9821cd79abaa734322de26 ] Original code assumed fixed and correct BTF header length. That's not always the case, though, so fix this bug with a proper additional check. And use actual header length instead of sizeof(struct btf_header) in sanity checks. Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf") Reported-by: Evgeny Vereshchagin Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211023003157.726961-2-andrii@kernel.org Signed-off-by: Sasha Levin --- tools/lib/bpf/btf.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 3e3ecac43ea9b..7ab9f702e72ac 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -231,13 +231,19 @@ static int btf_parse_hdr(struct btf *btf) } btf_bswap_hdr(hdr); } else if (hdr->magic != BTF_MAGIC) { - pr_debug("Invalid BTF magic:%x\n", hdr->magic); + pr_debug("Invalid BTF magic: %x\n", hdr->magic); return -EINVAL; } - meta_left = btf->raw_size - sizeof(*hdr); + if (btf->raw_size < hdr->hdr_len) { + pr_debug("BTF header len %u larger than data size %u\n", + hdr->hdr_len, btf->raw_size); + return -EINVAL; + } + + meta_left = btf->raw_size - hdr->hdr_len; if (meta_left < (long long)hdr->str_off + hdr->str_len) { - pr_debug("Invalid BTF total size:%u\n", btf->raw_size); + pr_debug("Invalid BTF total size: %u\n", btf->raw_size); return -EINVAL; } -- 2.33.0