commit 1c73d0b29d04bf4082e7beb6a508895e118ee30d upstream.
As pointed by smatch:
drivers/media/usb/dvb-usb/dw2102.c:802 su3000_i2c_transfer() error: __builtin_memcpy() '&state->data[4]' too small (64 vs 67)
That seemss to be due to a wrong copy-and-paste.
Fixes: 0e148a522b84 ("media: dw2102: Don't translate i2c read into write")
Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0e148a522b8453115038193e19ec7bea71403e4a ]
The code ignored the I2C_M_RD flag on I2C messages. Instead it assumed
an i2c transaction with a single message must be a write operation and a
transaction with two messages would be a read operation.
Though this works for the driver code, it leads to problems once the i2c
device is exposed to code not knowing this convention. For example,
I did "insmod i2c-dev" and issued read requests from userspace, which
were translated into write requests and destroyed the EEPROM of my
device.
So, just check and respect the I2C_M_READ flag, which indicates a read
when set on a message. If it is absent, it is a write message.
Incidentally, changing from the case statement to a while loop allows
the code to lift the limitation to two i2c messages per transaction.
There are 4 more *_i2c_transfer functions affected by the same behaviour
and limitation that should be fixed in the same way.
Link: https://lore.kernel.org/linux-media/20220116112238.74171-2-micha@freedict.org
Signed-off-by: Michael Bunk <micha@freedict.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
