From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 019542F5319; Tue, 2 Sep 2025 13:41:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756820514; cv=none; b=U0xo4PoGE2dv+MqIbLyV+XTfslPdZaVuqQkrP7HYRFenatI9wi/x0vwbc+qhv//hbwpND0bYctYHPG6HJ7bbGy9hN4UjuGUilndl0jBsn2lIQL4gD6pohKUn6Sfwn6gNdZOo+F8XHjI9ZgTyV2dzLkX5ODrRxRHCgvSRx1ypk5w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756820514; c=relaxed/simple; bh=61r7OPgM56ggpRYji+0qaXT8idLaxMapP7ggxAaJUPI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OahT/0cERidOVl+7vzcxSPtgBA1sG/VBdFQRhLq5eMy9JrxYXTTFCIDcLmv2xTD0KJOH0vh76bJ8TJYP3+zleoimCdAiT0YK/hrKBMpTqhrTsVMeeBBts/ANOHxDfUAOycyhj3CA6gmfK9Dv/59z15LmBoyj1PsUD6x1BQRliUA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ruea95HY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ruea95HY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64379C4CEED; Tue, 2 Sep 2025 13:41:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756820513; bh=61r7OPgM56ggpRYji+0qaXT8idLaxMapP7ggxAaJUPI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ruea95HY+KDrnAtX/pKwo+2IzWWFwo+Ho0I3voHycvar7+J24bbnyHTd3CT0yFEIk rcLXf5xYmM7Duix5eeNT/7kCNCkJ28RPXPlLh8RJKdVnflptfu+0zf5hoH/Tazx98h Xv2OXY7Ym2XnTF4uOgDUciI8flG046hKX8i6IoIo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qasim Ijaz , Benjamin Tissoires Subject: [PATCH 6.1 36/50] HID: asus: fix UAF via HID_CLAIMED_INPUT validation Date: Tue, 2 Sep 2025 15:21:27 +0200 Message-ID: <20250902131931.957421402@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250902131930.509077918@linuxfoundation.org> References: <20250902131930.509077918@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qasim Ijaz commit d3af6ca9a8c34bbd8cff32b469b84c9021c9e7e4 upstream. After hid_hw_start() is called hidinput_connect() will eventually be called to set up the device with the input layer since the HID_CONNECT_DEFAULT connect mask is used. During hidinput_connect() all input and output reports are processed and corresponding hid_inputs are allocated and configured via hidinput_configure_usages(). This process involves slot tagging report fields and configuring usages by setting relevant bits in the capability bitmaps. However it is possible that the capability bitmaps are not set at all leading to the subsequent hidinput_has_been_populated() check to fail leading to the freeing of the hid_input and the underlying input device. This becomes problematic because a malicious HID device like a ASUS ROG N-Key keyboard can trigger the above scenario via a specially crafted descriptor which then leads to a user-after-free when the name of the freed input device is written to later on after hid_hw_start(). Below, report 93 intentionally utilises the HID_UP_UNDEFINED Usage Page which is skipped during usage configuration, leading to the frees. 0x05, 0x0D, // Usage Page (Digitizer) 0x09, 0x05, // Usage (Touch Pad) 0xA1, 0x01, // Collection (Application) 0x85, 0x0D, // Report ID (13) 0x06, 0x00, 0xFF, // Usage Page (Vendor Defined 0xFF00) 0x09, 0xC5, // Usage (0xC5) 0x15, 0x00, // Logical Minimum (0) 0x26, 0xFF, 0x00, // Logical Maximum (255) 0x75, 0x08, // Report Size (8) 0x95, 0x04, // Report Count (4) 0xB1, 0x02, // Feature (Data,Var,Abs) 0x85, 0x5D, // Report ID (93) 0x06, 0x00, 0x00, // Usage Page (Undefined) 0x09, 0x01, // Usage (0x01) 0x15, 0x00, // Logical Minimum (0) 0x26, 0xFF, 0x00, // Logical Maximum (255) 0x75, 0x08, // Report Size (8) 0x95, 0x1B, // Report Count (27) 0x81, 0x02, // Input (Data,Var,Abs) 0xC0, // End Collection Below is the KASAN splat after triggering the UAF: [ 21.672709] ================================================================== [ 21.673700] BUG: KASAN: slab-use-after-free in asus_probe+0xeeb/0xf80 [ 21.673700] Write of size 8 at addr ffff88810a0ac000 by task kworker/1:2/54 [ 21.673700] [ 21.673700] CPU: 1 UID: 0 PID: 54 Comm: kworker/1:2 Not tainted 6.16.0-rc4-g9773391cf4dd-dirty #36 PREEMPT(voluntary) [ 21.673700] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 21.673700] Call Trace: [ 21.673700] [ 21.673700] dump_stack_lvl+0x5f/0x80 [ 21.673700] print_report+0xd1/0x660 [ 21.673700] kasan_report+0xe5/0x120 [ 21.673700] __asan_report_store8_noabort+0x1b/0x30 [ 21.673700] asus_probe+0xeeb/0xf80 [ 21.673700] hid_device_probe+0x2ee/0x700 [ 21.673700] really_probe+0x1c6/0x6b0 [ 21.673700] __driver_probe_device+0x24f/0x310 [ 21.673700] driver_probe_device+0x4e/0x220 [...] [ 21.673700] [ 21.673700] Allocated by task 54: [ 21.673700] kasan_save_stack+0x3d/0x60 [ 21.673700] kasan_save_track+0x18/0x40 [ 21.673700] kasan_save_alloc_info+0x3b/0x50 [ 21.673700] __kasan_kmalloc+0x9c/0xa0 [ 21.673700] __kmalloc_cache_noprof+0x139/0x340 [ 21.673700] input_allocate_device+0x44/0x370 [ 21.673700] hidinput_connect+0xcb6/0x2630 [ 21.673700] hid_connect+0xf74/0x1d60 [ 21.673700] hid_hw_start+0x8c/0x110 [ 21.673700] asus_probe+0x5a3/0xf80 [ 21.673700] hid_device_probe+0x2ee/0x700 [ 21.673700] really_probe+0x1c6/0x6b0 [ 21.673700] __driver_probe_device+0x24f/0x310 [ 21.673700] driver_probe_device+0x4e/0x220 [...] [ 21.673700] [ 21.673700] Freed by task 54: [ 21.673700] kasan_save_stack+0x3d/0x60 [ 21.673700] kasan_save_track+0x18/0x40 [ 21.673700] kasan_save_free_info+0x3f/0x60 [ 21.673700] __kasan_slab_free+0x3c/0x50 [ 21.673700] kfree+0xcf/0x350 [ 21.673700] input_dev_release+0xab/0xd0 [ 21.673700] device_release+0x9f/0x220 [ 21.673700] kobject_put+0x12b/0x220 [ 21.673700] put_device+0x12/0x20 [ 21.673700] input_free_device+0x4c/0xb0 [ 21.673700] hidinput_connect+0x1862/0x2630 [ 21.673700] hid_connect+0xf74/0x1d60 [ 21.673700] hid_hw_start+0x8c/0x110 [ 21.673700] asus_probe+0x5a3/0xf80 [ 21.673700] hid_device_probe+0x2ee/0x700 [ 21.673700] really_probe+0x1c6/0x6b0 [ 21.673700] __driver_probe_device+0x24f/0x310 [ 21.673700] driver_probe_device+0x4e/0x220 [...] Fixes: 9ce12d8be12c ("HID: asus: Add i2c touchpad support") Cc: stable@vger.kernel.org Signed-off-by: Qasim Ijaz Link: https://patch.msgid.link/20250810181041.44874-1-qasdev00@gmail.com Signed-off-by: Benjamin Tissoires Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-asus.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/hid/hid-asus.c +++ b/drivers/hid/hid-asus.c @@ -1117,7 +1117,13 @@ static int asus_probe(struct hid_device return ret; } - if (!drvdata->input) { + /* + * Check that input registration succeeded. Checking that + * HID_CLAIMED_INPUT is set prevents a UAF when all input devices + * were freed during registration due to no usages being mapped, + * leaving drvdata->input pointing to freed memory. + */ + if (!drvdata->input || !(hdev->claimed & HID_CLAIMED_INPUT)) { hid_err(hdev, "Asus input not registered\n"); ret = -ENOMEM; goto err_stop_hw;