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 A975BC433F5 for ; Tue, 16 Nov 2021 01:14:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9471D60F5A for ; Tue, 16 Nov 2021 01:14:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378328AbhKPBRk (ORCPT ); Mon, 15 Nov 2021 20:17:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:44640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245168AbhKOTTn (ORCPT ); Mon, 15 Nov 2021 14:19:43 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6B4F66350B; Mon, 15 Nov 2021 18:29:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637000983; bh=lQxQVutVPwlRON39M/YBHJlk+mFQyhk+JdIwQsGqelw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D09nzu4djaXVsM+UiWOyFgr6BhrmOPV8gYht3FISIMOoxYMl7bTP5YEfhZxzrMpUV w6fipTiJOdkG2xmqyqCNU+vqvp6BuaGcUfxpN6VAewAWad8XyHkX4baIS0F5UoJTLN OFzk/BrpEBUfLh1tmg2hy7nR2KJHDS99w6pV8L9Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eli Billauer , Ziyang Xuan Subject: [PATCH 5.15 017/917] char: xillybus: fix msg_ep UAF in xillyusb_probe() Date: Mon, 15 Nov 2021 17:51:52 +0100 Message-Id: <20211115165429.319322456@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165428.722074685@linuxfoundation.org> References: <20211115165428.722074685@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: Ziyang Xuan commit 15c9a359094ec6251578b02387436bc64f11a477 upstream. When endpoint_alloc() return failed in xillyusb_setup_base_eps(), 'xdev->msg_ep' will be freed but not set to NULL. That lets program enter fail handling to cleanup_dev() in xillyusb_probe(). Check for 'xdev->msg_ep' is invalid in cleanup_dev() because 'xdev->msg_ep' did not set to NULL when was freed. So the UAF problem for 'xdev->msg_ep' is triggered. ================================================================== BUG: KASAN: use-after-free in fifo_mem_release+0x1f4/0x210 CPU: 0 PID: 166 Comm: kworker/0:2 Not tainted 5.15.0-rc5+ #19 Call Trace: dump_stack_lvl+0xe2/0x152 print_address_description.constprop.0+0x21/0x140 ? fifo_mem_release+0x1f4/0x210 kasan_report.cold+0x7f/0x11b ? xillyusb_probe+0x530/0x700 ? fifo_mem_release+0x1f4/0x210 fifo_mem_release+0x1f4/0x210 ? __sanitizer_cov_trace_pc+0x1d/0x50 endpoint_dealloc+0x35/0x2b0 cleanup_dev+0x90/0x120 xillyusb_probe+0x59a/0x700 ... Freed by task 166: kasan_save_stack+0x1b/0x40 kasan_set_track+0x1c/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x109/0x140 kfree+0x117/0x4c0 xillyusb_probe+0x606/0x700 Set 'xdev->msg_ep' to NULL after being freed in xillyusb_setup_base_eps() to fix the UAF problem. Fixes: a53d1202aef1 ("char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)") Cc: stable Acked-by: Eli Billauer Signed-off-by: Ziyang Xuan Link: https://lore.kernel.org/r/20211016052047.1611983-1-william.xuanziyang@huawei.com Signed-off-by: Greg Kroah-Hartman --- drivers/char/xillybus/xillyusb.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/char/xillybus/xillyusb.c +++ b/drivers/char/xillybus/xillyusb.c @@ -1912,6 +1912,7 @@ static int xillyusb_setup_base_eps(struc dealloc: endpoint_dealloc(xdev->msg_ep); /* Also frees FIFO mem if allocated */ + xdev->msg_ep = NULL; return -ENOMEM; }