From: Atul Gopinathan atulgopinathan@gmail.com

commit e78836ae76d20f38eed8c8c67f21db97529949da upstream.

The "u16 CcxRmState[2];" array field in struct "rtllib_network" has 4 bytes in total while the operations performed on this array through-out the code base are only 2 bytes.

The "CcxRmState" field is fed only 2 bytes of data using memcpy():

(In rtllib_rx.c:1972) memcpy(network->CcxRmState, &info_element->data[4], 2)

With "info_element->data[]" being a u8 array, if 2 bytes are written into "CcxRmState" (whose one element is u16 size), then the 2 u8 elements from "data[]" gets squashed and written into the first element ("CcxRmState[0]") while the second element ("CcxRmState[1]") is never fed with any data.

Same in file rtllib_rx.c:2522: memcpy(dst->CcxRmState, src->CcxRmState, 2);

The above line duplicates "src" data to "dst" but only writes 2 bytes (and not 4, which is the actual size). Again, only 1st element gets the value while the 2nd element remains uninitialized.

This later makes operations done with CcxRmState unpredictable in the following lines as the 1st element is having a squashed number while the 2nd element is having an uninitialized random number.

rtllib_rx.c:1973: if (network->CcxRmState[0] != 0) rtllib_rx.c:1977: network->MBssidMask = network->CcxRmState[1] & 0x07;

network->MBssidMask is also of type u8 and not u16.

Fix this by changing the type of "CcxRmState" from u16 to u8 so that the data written into this array and read from it make sense and are not random values.

NOTE: The wrong initialization of "CcxRmState" can be seen in the following commit:

commit ecdfa44610fa ("Staging: add Realtek 8192 PCI wireless driver")

The above commit created a file `rtl8192e/ieee80211.h` which used to have the faulty line. The file has been deleted (or possibly renamed) with the contents copied in to a new file `rtl8192e/rtllib.h` along with additional code in the commit 94a799425eee (tagged in Fixes).

Fixes: 94a799425eee ("From: wlanfae wlanfae@realtek.com [PATCH 1/8] rtl8192e: Import new version of driver from realtek") Cc: stable@vger.kernel.org Signed-off-by: Atul Gopinathan atulgopinathan@gmail.com Link: https://lore.kernel.org/r/20210323113413.29179-2-atulgopinathan@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/rtl8192e/rtllib.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8192e/rtllib.h b/drivers/staging/rtl8192e/rtllib.h index c01474a6db1e8..2574275475d16 100644 --- a/drivers/staging/rtl8192e/rtllib.h +++ b/drivers/staging/rtl8192e/rtllib.h @@ -1110,7 +1110,7 @@ struct rtllib_network { bool bWithAironetIE; bool bCkipSupported; bool bCcxRmEnable; - u16 CcxRmState[2]; + u8 CcxRmState[2]; bool bMBssidValid; u8 MBssidMask; u8 MBssid[ETH_ALEN];