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Commit 91a0e1ed authored by Stephen Douthit's avatar Stephen Douthit Committed by Greg Kroah-Hartman
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i2c: ismt: Return EMSGSIZE for block reads with bogus length 



commit ba201c4f5ebe13d7819081756378777d8153f23e upstream.

Compare the number of bytes actually seen on the wire to the byte
count field returned by the slave device.

Previously we just overwrote the byte count returned by the slave
with the real byte count and let the caller figure out if the
message was sane.

Signed-off-by: default avatarStephen Douthit <stephend@adiengineering.com>
Tested-by: default avatarDan Priamo <danp@adiengineering.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d22f6da4

drivers/i2c/busses/i2c-ismt.c

+3 −1
Original line number Diff line number Diff line
@@ -341,8 +341,10 @@ static int ismt_process_desc(const struct ismt_desc *desc, 
			break;

		case I2C_SMBUS_BLOCK_DATA:

		case I2C_SMBUS_I2C_BLOCK_DATA:

			if (desc->rxbytes != dma_buffer[0] + 1)

				return -EMSGSIZE;



			memcpy(data->block, dma_buffer, desc->rxbytes);

			data->block[0] = desc->rxbytes - 1;

			break;

		}

		return 0;