Return-path: Received: from mail-iy0-f174.google.com ([209.85.210.174]:61499 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754440Ab2BICaa (ORCPT ); Wed, 8 Feb 2012 21:30:30 -0500 Message-ID: <4F332FC3.7000808@lwfinger.net> (sfid-20120209_033054_939471_587C07F5) Date: Wed, 08 Feb 2012 20:30:27 -0600 From: Larry Finger MIME-Version: 1.0 To: Tim Gardner CC: Ben Hutchings , Chaoming Li , "John W. Linville" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rtlwifi: rtl8192se firmware load can overflow target buffer References: <1328735291-33220-1-git-send-email-tim.gardner@canonical.com> <1328737514.2627.14.camel@bwh-desktop> In-Reply-To: <1328737514.2627.14.camel@bwh-desktop> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 02/08/2012 03:45 PM, Ben Hutchings wrote: > On Wed, 2012-02-08 at 14:08 -0700, Tim Gardner wrote: >> The firmware file size check does not use the >> correct limit. >> >> Cc: Larry Finger >> Cc: Chaoming Li >> Cc: John W. Linville >> Cc: linux-wireless@vger.kernel.org >> Cc: netdev@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Tim Gardner >> --- >> drivers/net/wireless/rtlwifi/rtl8192se/fw.h | 3 ++- >> drivers/net/wireless/rtlwifi/rtl8192se/sw.c | 2 +- >> 2 files changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/net/wireless/rtlwifi/rtl8192se/fw.h b/drivers/net/wireless/rtlwifi/rtl8192se/fw.h >> index babe85d..5c377fc 100644 >> --- a/drivers/net/wireless/rtlwifi/rtl8192se/fw.h >> +++ b/drivers/net/wireless/rtlwifi/rtl8192se/fw.h >> @@ -30,6 +30,7 @@ >> #define __REALTEK_FIRMWARE92S_H__ >> >> #define RTL8190_MAX_FIRMWARE_CODE_SIZE 64000 >> +#define RTL8190_MAX_RAW_FIRMWARE_CODE_SIZE 164000 The current size of the firmware is 88,856, thus the value of RTL8190_MAX_RAW_FIRMWARE_CODE_SIZE should be set to 90,000 to allow for some growth in the size of the firmware. Using 164,000 wastes a lot of space. >> #define RTL8190_CPU_START_OFFSET 0x80 >> /* Firmware Local buffer size. 64k */ >> #define MAX_FIRMWARE_CODE_SIZE 0xFF00 >> @@ -217,7 +218,7 @@ struct rt_firmware { >> u8 fw_emem[RTL8190_MAX_FIRMWARE_CODE_SIZE]; >> u32 fw_imem_len; >> u32 fw_emem_len; >> - u8 sz_fw_tmpbuffer[164000]; >> + u8 sz_fw_tmpbuffer[RTL8190_MAX_RAW_FIRMWARE_CODE_SIZE]; >> u32 sz_fw_tmpbufferlen; >> u16 cmdpacket_fragthresold; >> }; >> diff --git a/drivers/net/wireless/rtlwifi/rtl8192se/sw.c b/drivers/net/wireless/rtlwifi/rtl8192se/sw.c >> index ca38dd9..155da0a 100644 >> --- a/drivers/net/wireless/rtlwifi/rtl8192se/sw.c >> +++ b/drivers/net/wireless/rtlwifi/rtl8192se/sw.c >> @@ -105,7 +105,7 @@ static void rtl92se_fw_cb(const struct firmware *firmware, void *context) >> rtlpriv->max_fw_size = 0; >> return; >> } >> - if (firmware->size> rtlpriv->max_fw_size) { >> + if (firmware->size>= RTL8190_MAX_RAW_FIRMWARE_CODE_SIZE) { Do not change this one. rtlpriv->max_fw_size has been set to sizeof(struct rt_firmware), which is correct. > > This appears to reject a firmware blob which is exactly the maximum > size, which looks wrong. Also doesn't this make the max_fw_size field > redundant? I commented on this one earlier, but to reiterate - max_fw_size is not redundant. Larry