linux/drivers/staging
Atul Gopinathan e78836ae76 staging: rtl8192e: Change state information from u16 to u8
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 ecdfa44610 ("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 94a799425e (tagged in Fixes).

Fixes: 94a799425e ("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>
2021-03-23 13:32:40 +01:00
..
android
axis-fifo
board
clocking-wizard
comedi
emxx_udc
fbtft
fieldbus
fsl-dpaa2
fwserial
gasket
gdm724x
greybus
gs_fpgaboot
hikey9xx
iio
kpc2000
ks7010
media
most
mt7621-dma
mt7621-dts
mt7621-pci
netlogic
nvec
octeon
octeon-usb
olpc_dcon
pi433
qlge
ralink-gdma
rtl8188eu
rtl8192e staging: rtl8192e: Change state information from u16 to u8 2021-03-23 13:32:40 +01:00
rtl8192u
rtl8712
rtl8723bs
rts5208
sm750fb
unisys
vc04_services
vme
vt6655
vt6656
wfx
wimax
wlan-ng
Kconfig
Makefile