From nobody Sat Jul 25 20:06:02 2026 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.2]) (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 1C06B3EB0E1; Tue, 14 Jul 2026 06:52:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.2 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784011948; cv=none; b=lNWqJH9OpVPO6AiKmwkvltRCveheN+y+LXOdeK+I4mUJ0sbsE1g2tqEZZSL6vhq24IjJaaor++oR/mt/+eellRYeWumQKAJkm6aOw+HIKEa2nzjpTK2ZIVEhJ1o1M910D/1NKhQs6keBCIDqIeGbiPINNKwdA+TMgKJvMcJk7R0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784011948; c=relaxed/simple; bh=6ACPL3xPY4kCzIozm4mfvh78P8la9Wyv79Is5pmDTXU=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=olOG9FuMAKGMO+9BDi+ynbQmeuQRaTe6+dhkvRuPd8YJHD4cj2E7HaAOuVB4V8HffbEH2KKTxY0+ebsXtyR8gGbridGwQTbNwNQ+dWCRxv2MYHrjdgPftmHzP6x0R/anX8vV3LN6v2Diioub9YLkD5/98oISKx9w4WmOvXPwiMk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=UgihLh84; arc=none smtp.client-ip=117.135.210.2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="UgihLh84" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=on YXaGprWzuvN/rin+WZnE7OSsL6l57M2UyUD/tPwgQ=; b=UgihLh84xx/q3YpzYQ paj03BhnyQT+1PhOg4+BqfTBLWAi1lRG/vTs/1Q6j2gN4X1awpfVjMcYDPJUNiSu FGT6bB+3mJ5wNw7YuHRNhrIK5FVrAdvOqL1Dlujhv9YiZQkXwCkwEYrZX395MJbv v7u3zS5rP0GYcPpja2DaVN+bQ= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g1-4 (Coremail) with SMTP id _____wBXlqWU3FVqGz8EJw--.28541S2; Tue, 14 Jul 2026 14:52:06 +0800 (CST) From: Lei Huang To: mchehab@kernel.org Cc: johan@kernel.org, hverkuil+cisco@kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Lei Huang Subject: [PATCH] media: s2255: check firmware size before reading trailing marker Date: Tue, 14 Jul 2026 14:52:02 +0800 Message-Id: <20260714065202.563027-1-huanglei814@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wBXlqWU3FVqGz8EJw--.28541S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrtF13XF1UCr4xtw13CryxAFb_yoWkurb_ur n7uw1kG3W0yry5Wr42kr1SvrWrArW8Wr1ruFn2q3W5J3yjqa1UXr4DZw1Iq3Z8GanFyF1U Jas5XF4fuwn8WjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU8xwIDUUUUU== X-CM-SenderInfo: xkxd0wxohlmiqu6rljoofrz/xtbC9BZMQ2pV3JZ8DgAA3q Content-Type: text/plain; charset="utf-8" From: Lei Huang s2255_probe() reads a 4-byte marker and version from the last 8 bytes of the firmware blob (fw->data[fw_size - 8] and [fw_size - 4]). If the firmware file is shorter than 8 bytes, fw_size - 8 underflows and the access reads out of bounds. Validate the firmware size before indexing. Fixes: 14d962602c8b ("V4L/DVB (8752): s2255drv: firmware improvement patch") Signed-off-by: Lei Huang --- drivers/media/usb/s2255/s2255drv.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s= 2255drv.c index 0b8182edf8e4..3917913c3b47 100644 --- a/drivers/media/usb/s2255/s2255drv.c +++ b/drivers/media/usb/s2255/s2255drv.c @@ -2277,6 +2277,11 @@ static int s2255_probe(struct usb_interface *interfa= ce, } /* check the firmware is valid */ fw_size =3D dev->fw_data->fw->size; + if (fw_size < 8) { + dev_err(&interface->dev, "Firmware invalid: too small.\n"); + retval =3D -ENODEV; + goto errorFWMARKER; + } pdata =3D (__le32 *) &dev->fw_data->fw->data[fw_size - 8]; =20 if (*pdata !=3D S2255_FW_MARKER) { --=20 2.25.1