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 C2A2DC3525A for ; Mon, 24 Jan 2022 23:07:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1842645AbiAXXCU (ORCPT ); Mon, 24 Jan 2022 18:02:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1456427AbiAXVzC (ORCPT ); Mon, 24 Jan 2022 16:55:02 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1A21C07E28E; Mon, 24 Jan 2022 12:35:46 -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 ams.source.kernel.org (Postfix) with ESMTPS id 7F655B80FA1; Mon, 24 Jan 2022 20:35:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A68D3C340E5; Mon, 24 Jan 2022 20:35:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643056544; bh=OzfIY9xRVRlOTpRoanuZo2T6HA3to4jATFB0/K4WRxs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YrsoDINTgSwlrg/k8j36Qy/MlRyFdh5o5rmFA2VWTaGblOBykvit46GIcKr6lP8r+ tyV29stQZmltgaK2i64MhsnO+XTXwsAdaBZCfv4xTZegkAMqmAC/ErlFbVjL1hsYSz qoTqtIr6cCQ8aYcng+Yfvd1KTeWcaoxJtqjIZu5M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+23a02c7df2cf2bc93fa2@syzkaller.appspotmail.com, Xiongwei Song , Denis Efremov , Jens Axboe , Sasha Levin Subject: [PATCH 5.15 520/846] floppy: Add max size check for user space request Date: Mon, 24 Jan 2022 19:40:37 +0100 Message-Id: <20220124184118.952832171@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184100.867127425@linuxfoundation.org> References: <20220124184100.867127425@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: Xiongwei Song [ Upstream commit 545a32498c536ee152331cd2e7d2416aa0f20e01 ] We need to check the max request size that is from user space before allocating pages. If the request size exceeds the limit, return -EINVAL. This check can avoid the warning below from page allocator. WARNING: CPU: 3 PID: 16525 at mm/page_alloc.c:5344 current_gfp_context include/linux/sched/mm.h:195 [inline] WARNING: CPU: 3 PID: 16525 at mm/page_alloc.c:5344 __alloc_pages+0x45d/0x500 mm/page_alloc.c:5356 Modules linked in: CPU: 3 PID: 16525 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 RIP: 0010:__alloc_pages+0x45d/0x500 mm/page_alloc.c:5344 Code: be c9 00 00 00 48 c7 c7 20 4a 97 89 c6 05 62 32 a7 0b 01 e8 74 9a 42 07 e9 6a ff ff ff 0f 0b e9 a0 fd ff ff 40 80 e5 3f eb 88 <0f> 0b e9 18 ff ff ff 4c 89 ef 44 89 e6 45 31 ed e8 1e 76 ff ff e9 RSP: 0018:ffffc90023b87850 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff92004770f0b RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000033 RDI: 0000000000010cc1 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81bb4686 R11: 0000000000000001 R12: ffffffff902c1960 R13: 0000000000000033 R14: 0000000000000000 R15: ffff88804cf64a30 FS: 0000000000000000(0000) GS:ffff88802cd00000(0063) knlGS:00000000f44b4b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000002c921000 CR3: 000000004f507000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 __get_free_pages+0x8/0x40 mm/page_alloc.c:5418 raw_cmd_copyin drivers/block/floppy.c:3113 [inline] raw_cmd_ioctl drivers/block/floppy.c:3160 [inline] fd_locked_ioctl+0x12e5/0x2820 drivers/block/floppy.c:3528 fd_ioctl drivers/block/floppy.c:3555 [inline] fd_compat_ioctl+0x891/0x1b60 drivers/block/floppy.c:3869 compat_blkdev_ioctl+0x3b8/0x810 block/ioctl.c:662 __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:972 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c Reported-by: syzbot+23a02c7df2cf2bc93fa2@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20211116131033.27685-1-sxwjean@me.com Signed-off-by: Xiongwei Song Signed-off-by: Denis Efremov Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/floppy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index f50bbaba5762c..4a6a74177b3c9 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3080,6 +3080,8 @@ static void raw_cmd_free(struct floppy_raw_cmd **ptr) } } +#define MAX_LEN (1UL << MAX_ORDER << PAGE_SHIFT) + static int raw_cmd_copyin(int cmd, void __user *param, struct floppy_raw_cmd **rcmd) { @@ -3107,7 +3109,7 @@ loop: ptr->resultcode = 0; if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) { - if (ptr->length <= 0) + if (ptr->length <= 0 || ptr->length >= MAX_LEN) return -EINVAL; ptr->kernel_data = (char *)fd_dma_mem_alloc(ptr->length); fallback_on_nodma_alloc(&ptr->kernel_data, ptr->length); -- 2.34.1