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 77C54EEA6; Thu, 24 Jul 2025 07:01:27 +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=1753340487; cv=none; b=vBGb4inNXEg7buFxYTQTm98oDQLl22LNGj/Ld9tz+Q1lqXjNncBzYVRXhWEuIxOWuRGoEQRspXMwGJCT70TqNCvrGRp/ZFD5O3qbQoi1sQHqt9cKnXPjz+igUKhcRW7GugxUqgV1Rk+x1s3Ze4M2BnBTAoW72Ny5A/SeT4xalYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753340487; c=relaxed/simple; bh=tuq6Rmgg5VT6PaXnAV5s/mubX6mQSTO5YzbVqh22Nv4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rW+mMRtMSSXc0BpYKmGmbM0E0WHu9X2NNyL1bomghxIZvjRD0LItunWn34nmrbRmxicolzcIrWnTTMTmSVnZrGvSv5BKh7EuOvzkpEyrbo1UIk/t9QFR+W2nZe4rbJOStT6a7j7DAnxqGZU/P2J4Fr3levFLygCz9M/peLnSftk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=t1GrbAp9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="t1GrbAp9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99A56C4CEED; Thu, 24 Jul 2025 07:01:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753340487; bh=tuq6Rmgg5VT6PaXnAV5s/mubX6mQSTO5YzbVqh22Nv4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=t1GrbAp9Ix4dXQayW38sTtqu6z3Z1oo8eNmtzOMA5jeRm5cAT33CsgAvD1VehjLMd I31FeCAy+yVK7O43klAFYHv4DoAgBay8yjr4uHT5wJwS8alTrQJq1QTnuyKOzW3kkw mlmH1JGxYAJGDQJCtX+/oT221bW1U+lF9fixSd/syQUdG7iSoUXBsEJge1sCOZPJBb zyK6PHkSsB7SOq6y7IcO5OhBfupNoA7X/wpXbfRr+3c7hShL4bv5hvPYg+VG53qgDi dF+5R/johiOYvmSTQh+UKxU9hhPgwT12X94tLKdnGDkEKNSygo0adtbctMrJyY1/Xh 9a/JHqca61d6g== Message-ID: <0541891e-2631-43fa-8f3c-a7afb83436b2@kernel.org> Date: Thu, 24 Jul 2025 09:01:24 +0200 Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] HID: multitouch: fix slab out-of-bounds access in mt_report_fixup() To: Qasim Ijaz , jikos@kernel.org, bentiss@kernel.org Cc: envelsavinds@gmail.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20250723110036.24439-1-qasdev00@gmail.com> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 23. 07. 25, 13:00, Qasim Ijaz wrote: > A malicious HID device can trigger a slab out-of-bounds during > mt_report_fixup() by passing in report descriptor smaller than > 607 bytes. mt_report_fixup() attempts to patch byte offset 607 > of the descriptor with 0x25 by first checking if byte offset > 607 is 0x15 however it lacks bounds checks to verify if the > descriptor is big enough before conducting this check. Fix > this bug by ensuring the descriptor size is at least 608 > bytes before accessing it. > > Below is the KASAN splat after the out of bounds access happens: > > [ 13.671954] ================================================================== > [ 13.672667] BUG: KASAN: slab-out-of-bounds in mt_report_fixup+0x103/0x110 ... > [...] > > Fixes: c8000deb6836 ("HID: multitouch: Add support for GT7868Q") > Cc: stable@vger.kernel.org > Signed-off-by: Qasim Ijaz LGTM Reviewed-by: Jiri Slaby > --- a/drivers/hid/hid-multitouch.c > +++ b/drivers/hid/hid-multitouch.c > @@ -1503,6 +1503,14 @@ static const __u8 *mt_report_fixup(struct hid_device *hdev, __u8 *rdesc, > if (hdev->vendor == I2C_VENDOR_ID_GOODIX && > (hdev->product == I2C_DEVICE_ID_GOODIX_01E8 || > hdev->product == I2C_DEVICE_ID_GOODIX_01E9)) { > + if (*size < 608) { > + dev_info( Except I would not add \n to the line above. > + &hdev->dev, > + "GT7868Q fixup: report descriptor is only %u bytes, skipping\n", > + *size); > + return rdesc; > + } > + > if (rdesc[607] == 0x15) { > rdesc[607] = 0x25; > dev_info( thanks, -- js suse labs