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 BAFD1C41513 for ; Mon, 16 Oct 2023 14:47:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232564AbjJPOru (ORCPT ); Mon, 16 Oct 2023 10:47:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232660AbjJPOrt (ORCPT ); Mon, 16 Oct 2023 10:47:49 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5CDB95 for ; Mon, 16 Oct 2023 07:47:47 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06202C433C8; Mon, 16 Oct 2023 14:47:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1697467667; bh=X2UsUDHLdeRX2QZ8UjUvaXl7a8grjYMWxbEt9XpecmY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RD23t7AHeNnDlUCt+veyphtzsVIGZFhZmG1tUXMl9mSRzM5UcUODwNJXySk2bqta1 FrQh+LopaXfEsnZYfSSqLukoHYUAvpCBJGSF359xnzxBFDpMrtLfKG17PSZk86Ob5Z +F7YDjuWBcuOiZQyBgBXVLWgOQuaUuoVVVyRJ4uE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+fae676d3cf469331fc89@syzkaller.appspotmail.com, syzbot+b132693e925cbbd89e26@syzkaller.appspotmail.com, Andrew Kanner , Daniel Borkmann , Magnus Karlsson , Sasha Levin Subject: [PATCH 6.5 067/191] xdp: Fix zero-size allocation warning in xskq_create() Date: Mon, 16 Oct 2023 10:40:52 +0200 Message-ID: <20231016084016.970413131@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231016084015.400031271@linuxfoundation.org> References: <20231016084015.400031271@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Kanner [ Upstream commit a12bbb3cccf03b12847de0f7a6772127f90936ac ] Syzkaller reported the following issue: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2807 at mm/vmalloc.c:3247 __vmalloc_node_range (mm/vmalloc.c:3361) Modules linked in: CPU: 0 PID: 2807 Comm: repro Not tainted 6.6.0-rc2+ #12 Hardware name: Generic DT based system unwind_backtrace from show_stack (arch/arm/kernel/traps.c:258) show_stack from dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1)) dump_stack_lvl from __warn (kernel/panic.c:633 kernel/panic.c:680) __warn from warn_slowpath_fmt (./include/linux/context_tracking.h:153 kernel/panic.c:700) warn_slowpath_fmt from __vmalloc_node_range (mm/vmalloc.c:3361 (discriminator 3)) __vmalloc_node_range from vmalloc_user (mm/vmalloc.c:3478) vmalloc_user from xskq_create (net/xdp/xsk_queue.c:40) xskq_create from xsk_setsockopt (net/xdp/xsk.c:953 net/xdp/xsk.c:1286) xsk_setsockopt from __sys_setsockopt (net/socket.c:2308) __sys_setsockopt from ret_fast_syscall (arch/arm/kernel/entry-common.S:68) xskq_get_ring_size() uses struct_size() macro to safely calculate the size of struct xsk_queue and q->nentries of desc members. But the syzkaller repro was able to set q->nentries with the value initially taken from copy_from_sockptr() high enough to return SIZE_MAX by struct_size(). The next PAGE_ALIGN(size) is such case will overflow the size_t value and set it to 0. This will trigger WARN_ON_ONCE in vmalloc_user() -> __vmalloc_node_range(). The issue is reproducible on 32-bit arm kernel. Fixes: 9f78bf330a66 ("xsk: support use vaddr as ring") Reported-by: syzbot+fae676d3cf469331fc89@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000c84b4705fb31741e@google.com/T/ Reported-by: syzbot+b132693e925cbbd89e26@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000e20df20606ebab4f@google.com/T/ Signed-off-by: Andrew Kanner Signed-off-by: Daniel Borkmann Tested-by: syzbot+fae676d3cf469331fc89@syzkaller.appspotmail.com Acked-by: Magnus Karlsson Link: https://syzkaller.appspot.com/bug?extid=fae676d3cf469331fc89 Link: https://lore.kernel.org/bpf/20231007075148.1759-1-andrew.kanner@gmail.com Signed-off-by: Sasha Levin --- net/xdp/xsk_queue.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c index f8905400ee07a..d2c2640300171 100644 --- a/net/xdp/xsk_queue.c +++ b/net/xdp/xsk_queue.c @@ -34,6 +34,16 @@ struct xsk_queue *xskq_create(u32 nentries, bool umem_queue) q->ring_mask = nentries - 1; size = xskq_get_ring_size(q, umem_queue); + + /* size which is overflowing or close to SIZE_MAX will become 0 in + * PAGE_ALIGN(), checking SIZE_MAX is enough due to the previous + * is_power_of_2(), the rest will be handled by vmalloc_user() + */ + if (unlikely(size == SIZE_MAX)) { + kfree(q); + return NULL; + } + size = PAGE_ALIGN(size); q->ring = vmalloc_user(size); -- 2.40.1