[PATCH 4.8 002/138] i2c: xgene: Avoid dma_buffer overrun

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hoan Tran <hotran@xxxxxxx>

commit 603616017c35f4d0fbdbcace72adf9bf949c4a65 upstream.

SMBus block command uses the first byte of buffer for the data length.
The dma_buffer should be increased by 1 to avoid the overrun issue.

Reported-by: Phil Endecott <phil_gjouf_endecott@xxxxxxxxxxxx>
Signed-off-by: Hoan Tran <hotran@xxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/i2c/busses/i2c-xgene-slimpro.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/i2c/busses/i2c-xgene-slimpro.c
+++ b/drivers/i2c/busses/i2c-xgene-slimpro.c
@@ -105,7 +105,7 @@ struct slimpro_i2c_dev {
 	struct mbox_chan *mbox_chan;
 	struct mbox_client mbox_client;
 	struct completion rd_complete;
-	u8 dma_buffer[I2C_SMBUS_BLOCK_MAX];
+	u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* dma_buffer[0] is used for length */
 	u32 *resp_msg;
 };