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 EB26929E112 for ; Mon, 24 Nov 2025 19:20:51 +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=1764012052; cv=none; b=AbzbHK7FK0DuAlEofoE0RVpss+8mByzF2WjRM+kdkfPpCmyF1n67ltoSbz1PG+nHQvuNbOIA/wLNWba2Gu7U2ePPEkbwo8ImmS72yg/0zPXQ0hrpcd8oy8wrEjjADwAVROnLpAxrxPcWFiCf5lqPRf+DjPMr38isFJKok2LQmPU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764012052; c=relaxed/simple; bh=E2JOMDEr8z+GMmz/BATIesSjQcVM1L0IzGNQ0lQeT4A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=er0ZqGzRiFG2/ca/ZpcZgwLhTL8vqVkxoy8UEJ8r3jHWDGkt1Mz/b91Tsa5fEjok1aT6IgwSDVaxoo9DgYQG/bYf4x7lZnsiRmW+aFOqT9PPvs6WZfG2iCzpukUuf5Vub13c9RgIAwQ/+FYSt86AtxrBIEBP6cwSIDi/b9aEh00= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=P5Q128Ju; 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="P5Q128Ju" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E09FEC4CEF1; Mon, 24 Nov 2025 19:20:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764012051; bh=E2JOMDEr8z+GMmz/BATIesSjQcVM1L0IzGNQ0lQeT4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P5Q128Ju3tIwf9zLF6A9ksE1gTxSMFBMyNXHyyQVafocsIZjOfMVg7moQl1tj2RBV nLrrSOxlEokJdDUSiydDsxr5nLC87OGOj4XSQ+TuHWb8BfRkBJm8A4Vnymxd1cJNjf F573NOU+3MNXh/gu4TLVwmk/2VvD1Kq0oNfUf2I/1JwYpkJ1/1g8qzK0N/DmpvI1Qg yK6ouo7/mmFY6ON0Np7qlYandVADPGI6Fo3xtVE7J5BUthc9/1UbpaDwHt4DKezc8J b7rZ+9cFWRJCbmHuhmVdH9WW/K+srN1CN0WTm2LppfvLH220dtm1Y2/uB+3Ss5lCAS 1jAesDrYCA58g== From: Sasha Levin To: stable@vger.kernel.org Cc: Seungjin Bae , Dmitry Torokhov , Sasha Levin Subject: [PATCH 5.4.y 3/3] Input: pegasus-notetaker - fix potential out-of-bounds access Date: Mon, 24 Nov 2025 14:20:46 -0500 Message-ID: <20251124192046.3812-3-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251124192046.3812-1-sashal@kernel.org> References: <2025112420-barman-maybe-9927@gregkh> <20251124192046.3812-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Seungjin Bae [ Upstream commit 69aeb507312306f73495598a055293fa749d454e ] In the pegasus_notetaker driver, the pegasus_probe() function allocates the URB transfer buffer using the wMaxPacketSize value from the endpoint descriptor. An attacker can use a malicious USB descriptor to force the allocation of a very small buffer. Subsequently, if the device sends an interrupt packet with a specific pattern (e.g., where the first byte is 0x80 or 0x42), the pegasus_parse_packet() function parses the packet without checking the allocated buffer size. This leads to an out-of-bounds memory access. Fixes: 1afca2b66aac ("Input: add Pegasus Notetaker tablet driver") Signed-off-by: Seungjin Bae Link: https://lore.kernel.org/r/20251007214131.3737115-2-eeodqql09@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin --- drivers/input/tablet/pegasus_notetaker.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/input/tablet/pegasus_notetaker.c b/drivers/input/tablet/pegasus_notetaker.c index 4e412a73a5aad..64a5ce5462293 100644 --- a/drivers/input/tablet/pegasus_notetaker.c +++ b/drivers/input/tablet/pegasus_notetaker.c @@ -63,6 +63,9 @@ #define BUTTON_PRESSED 0xb5 #define COMMAND_VERSION 0xa9 +/* 1 Status + 1 Color + 2 X + 2 Y = 6 bytes */ +#define NOTETAKER_PACKET_SIZE 6 + /* in xy data packet */ #define BATTERY_NO_REPORT 0x40 #define BATTERY_LOW 0x41 @@ -297,6 +300,12 @@ static int pegasus_probe(struct usb_interface *intf, pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress); pegasus->data_len = usb_maxpacket(dev, pipe); + if (pegasus->data_len < NOTETAKER_PACKET_SIZE) { + dev_err(&intf->dev, "packet size is too small (%d)\n", + pegasus->data_len); + error = -EINVAL; + goto err_free_mem; + } pegasus->data = usb_alloc_coherent(dev, pegasus->data_len, GFP_KERNEL, &pegasus->data_dma); -- 2.51.0