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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8647EC4708E for ; Mon, 5 Dec 2022 19:38:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234688AbiLETiR (ORCPT ); Mon, 5 Dec 2022 14:38:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233941AbiLEThx (ORCPT ); Mon, 5 Dec 2022 14:37:53 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CFC822AC46 for ; Mon, 5 Dec 2022 11:34:47 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6CE4361335 for ; Mon, 5 Dec 2022 19:34:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E559C433D6; Mon, 5 Dec 2022 19:34:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670268886; bh=pqjXRLDeDU42CC6W+w4CM5n80Y/ZLSl8ZW5c/RyXzPM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sw+96KDfIc0l6KxM4HXCcyNcwGI9rXe82s0QS2ELjC276IsZoR/2lwlPa3emw7jCJ HF6UNwktf8fTyX717hUeqlzEvC0ahhp32ExCsNqWNNjKD92hz4+id1Tny+pL4bqwp5 vLYE/rAV9WTvPzOck30/03ZcPAIFiyw6tAX2Mp8g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hou Tao , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.15 020/120] libbpf: Handle size overflow for ringbuf mmap Date: Mon, 5 Dec 2022 20:09:20 +0100 Message-Id: <20221205190807.180998122@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221205190806.528972574@linuxfoundation.org> References: <20221205190806.528972574@linuxfoundation.org> User-Agent: quilt/0.67 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: Hou Tao [ Upstream commit 927cbb478adf917e0a142b94baa37f06279cc466 ] The maximum size of ringbuf is 2GB on x86-64 host, so 2 * max_entries will overflow u32 when mapping producer page and data pages. Only casting max_entries to size_t is not enough, because for 32-bits application on 64-bits kernel the size of read-only mmap region also could overflow size_t. So fixing it by casting the size of read-only mmap region into a __u64 and checking whether or not there will be overflow during mmap. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Hou Tao Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221116072351.1168938-3-houtao@huaweicloud.com Signed-off-by: Sasha Levin --- tools/lib/bpf/ringbuf.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c index 8bc117bcc7bc..c42ba9358d8c 100644 --- a/tools/lib/bpf/ringbuf.c +++ b/tools/lib/bpf/ringbuf.c @@ -59,6 +59,7 @@ int ring_buffer__add(struct ring_buffer *rb, int map_fd, __u32 len = sizeof(info); struct epoll_event *e; struct ring *r; + __u64 mmap_sz; void *tmp; int err; @@ -97,8 +98,7 @@ int ring_buffer__add(struct ring_buffer *rb, int map_fd, r->mask = info.max_entries - 1; /* Map writable consumer page */ - tmp = mmap(NULL, rb->page_size, PROT_READ | PROT_WRITE, MAP_SHARED, - map_fd, 0); + tmp = mmap(NULL, rb->page_size, PROT_READ | PROT_WRITE, MAP_SHARED, map_fd, 0); if (tmp == MAP_FAILED) { err = -errno; pr_warn("ringbuf: failed to mmap consumer page for map fd=%d: %d\n", @@ -111,8 +111,12 @@ int ring_buffer__add(struct ring_buffer *rb, int map_fd, * data size to allow simple reading of samples that wrap around the * end of a ring buffer. See kernel implementation for details. * */ - tmp = mmap(NULL, rb->page_size + 2 * info.max_entries, PROT_READ, - MAP_SHARED, map_fd, rb->page_size); + mmap_sz = rb->page_size + 2 * (__u64)info.max_entries; + if (mmap_sz != (__u64)(size_t)mmap_sz) { + pr_warn("ringbuf: ring buffer size (%u) is too big\n", info.max_entries); + return libbpf_err(-E2BIG); + } + tmp = mmap(NULL, (size_t)mmap_sz, PROT_READ, MAP_SHARED, map_fd, rb->page_size); if (tmp == MAP_FAILED) { err = -errno; ringbuf_unmap_ring(rb, r); -- 2.35.1