From 538b96315375231ad4d749a81eda10fe737ea3e8 Mon Sep 17 00:00:00 2001 From: Atul Gopinathan Date: Tue, 23 Mar 2021 17:04:12 +0530 Subject: [PATCH] staging: rtl8192e: Fix incorrect source in memcpy() commit 72ad25fbbb78930f892b191637359ab5b94b3190 upstream. The variable "info_element" is of the following type: struct rtllib_info_element *info_element defined in drivers/staging/rtl8192e/rtllib.h: struct rtllib_info_element { u8 id; u8 len; u8 data[]; } __packed; The "len" field defines the size of the "data[]" array. The code is supposed to check if "info_element->len" is greater than 4 and later equal to 6. If this is satisfied then, the last two bytes (the 4th and 5th element of u8 "data[]" array) are copied into "network->CcxRmState". Right now the code uses "memcpy()" with the source as "&info_element[4]" which would copy in wrong and unintended information. The struct "rtllib_info_element" has a size of 2 bytes for "id" and "len", therefore indexing will be done in interval of 2 bytes. So, "info_element[4]" would point to data which is beyond the memory allocated for this pointer (that is, at x+8, while "info_element" has been allocated only from x to x+7 (2 + 6 => 8 bytes)). This patch rectifies this error by using "&info_element->data[4]" which correctly copies the last two bytes of "data[]". NOTE: The faulty line of code came from the following commit: commit ecdfa44610fa ("Staging: add Realtek 8192 PCI wireless driver") The above commit created the file `rtl8192e/ieee80211/ieee80211_rx.c` which had the faulty line of code. This file has been deleted (or possibly renamed) with the contents copied in to a new file `rtl8192e/rtllib_rx.c` along with additional code in the commit 94a799425eee (tagged in Fixes). Fixes: 94a799425eee ("From: wlanfae [PATCH 1/8] rtl8192e: Import new version of driver from realtek") Cc: stable@vger.kernel.org Signed-off-by: Atul Gopinathan Link: https://lore.kernel.org/r/20210323113413.29179-1-atulgopinathan@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rtl8192e/rtllib_rx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/rtl8192e/rtllib_rx.c b/drivers/staging/rtl8192e/rtllib_rx.c index d31b5e1..6375223 100644 --- a/drivers/staging/rtl8192e/rtllib_rx.c +++ b/drivers/staging/rtl8192e/rtllib_rx.c @@ -1968,7 +1968,7 @@ static void rtllib_parse_mife_generic(struct rtllib_device *ieee, info_element->data[2] == 0x96 && info_element->data[3] == 0x01) { if (info_element->len == 6) { - memcpy(network->CcxRmState, &info_element[4], 2); + memcpy(network->CcxRmState, &info_element->data[4], 2); if (network->CcxRmState[0] != 0) network->bCcxRmEnable = true; else -- 2.7.4