i2c: i801: Don't silently correct invalid transfer size
authorHeiner Kallweit <hkallweit1@gmail.com>
Sun, 7 Nov 2021 21:57:00 +0000 (22:57 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 07:47:39 +0000 (08:47 +0100)
commita126a8c3dd51519513141b4fc94fd4813bca2c0f
tree70207b79a4ec89f03569080fb365c296196c9aec
parentdc4b1e0b751033d41cb106b5018afeafb52603f0
i2c: i801: Don't silently correct invalid transfer size

[ Upstream commit effa453168a7eeb8a562ff4edc1dbf9067360a61 ]

If an invalid block size is provided, reject it instead of silently
changing it to a supported value. Especially critical I see the case of
a write transfer with block length 0. In this case we have no guarantee
that the byte we would write is valid. When silently reducing a read to
32 bytes then we don't return an error and the caller may falsely
assume that we returned the full requested data.

If this change should break any (broken) caller, then I think we should
fix the caller.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/i2c/busses/i2c-i801.c